Land Use Change and its Impact on Selected Biophysical and ...

KFRI Research Report No.298 ISSN 0970­8103<strong>L<strong>and</strong></strong> <strong>Use</strong> <strong>Change</strong> <strong>and</strong> <strong>its</strong> <strong>Impact</strong> on Selected Biophysical<strong>and</strong> Socio­economic Aspects of Karuvannur River Basinin Thrissur District of KeralaP.K. MuraleedharanJose KallarackalA.R.R. MenonM. BalagopalanN. SasidharanP. RugminiKerala Forest Research InstituteAn Institution of Kerala State Council for Science, Technology <strong>and</strong> EnvironmentPeechi 680 653, Thrissur, KeralaK F R INovember 2007

ABSTRACT OF THE PROJECT PROPOSAL1. Project No : KFRI/421/042. Title : <strong>L<strong>and</strong></strong> use change <strong>and</strong> <strong>its</strong> impact on selectedbiophysical <strong>and</strong> socioeconomic aspects of KaruvannurRiver Basin in Thrissur district of Kerala3. Objectives : Study the nature <strong>and</strong> extent of l<strong>and</strong>use <strong>and</strong>cropping pattern changes <strong>and</strong> important socio­economic drivers affecting it.4. Date of commencement : February 20045. Date of completion : April 2007: Examine the effects of l<strong>and</strong>use on hydrology­ runoff,stream flow, ground water table, temperature<strong>and</strong> humidity­ in the watershed.: Analyze the effects of l<strong>and</strong>use/cropping pattern changeson vegetation, sedimentation, agricultural production<strong>and</strong> socio­economic conditions of the people.: Assess economic value of water resource, surfacewater use pattern, pricing <strong>and</strong> use conflict over waterresources among different sections in the society.: Examine the linkages between ecological <strong>and</strong> socioeconomicsystems of the upl<strong>and</strong> <strong>and</strong> downstream areasof the watershed in determining overall development.6. Funding Agency : Ministry of Environment <strong>and</strong> Forests7. Investigators : P.K. MuraleedharanJose KallarackalA.R.R. MenonM. BalagopalanN. SasidharanP. Rugmini8. Research Fellows : John P. Inchakalody, P. Muhammed Rasheed <strong>and</strong>U.V. Deepa9. Study area : Karuvannur River Basin

CONTENTSACKNOWLEDGEMENTSABSTRACTi1. INTRODUCTION 11.1. The study area 21.2. Ecological <strong>and</strong> economic problems in the study area 51.3. Objectives 72. METHODOLOGY 92.1. Selection of micro watersheds 92.2. <strong>L<strong>and</strong></strong> use dynamics 92.3. Vegetation classification scheme 102.4. Digital classification of satellite data 112.5. Vegetation characterization using satellite data 112.6. Accuracy evaluation 122.7. Hydro meteorological observations 162.8. Water table fluctuation studies 172.9. Socio­economic aspects 182.10. Economic valuation of water resources 193. LAND USE AND CROPPING PATTERN CHANGES 273.1. <strong>L<strong>and</strong></strong> use change 273.2. Cropping pattern 333.3. <strong>L<strong>and</strong></strong> use <strong>and</strong> cropping pattern changes: Bio­physical <strong>and</strong> socio­economic drivers 354. HYDROLOGICAL STUDIES 414.1. Historical data on annual rainfall distribution 414.2. Average seasonal stream discharge at the study area 524.3. Ground water table 544.4. Water level in Peechi Reservoir 604.5. Temperature <strong>and</strong> relative humidity 624.6. Seasonal distribution of temperature 634.7. Relative humidity 644.8. Discussion 65

5. EFFECTS OF LAND USE/CROPPING PATTERN CHANGES ON VEGETATION,SEDIMENTATION AND SOCIO­ECONOMIC CONDITIONS OF THE PEOPLE 715.1. Plant diversity in the Olakara watershed area 715.2. Vegetation analysis 725.3. Sedimentation 755.4 Increase of production <strong>and</strong> productivity in agricultural sector 785.5. Socio­economics 796. VALUATION OF WATER RESOURCES AND USE CONFLICTS 836.1. Direct extractive benef<strong>its</strong> 836.2. Direct non­extractive benef<strong>its</strong> 846.3. Dem<strong>and</strong> function of tourists of Peechi Dam 846.4. Total recreational value 866.5. Indirect use value 866.6 Total estimated economic value 866.7. Pricing of water: some issues 876.8. Willingness to pay 896.9. Water use conflict 916.10. Sources of water in the study area 916.11. Irrigation vs. Drinking water 926.12. Conflict among farmers 946.13. Local level conflicts 957. LINKAGES BETWEEN UPLAND AND DOWN STREAM AREAS 97Upl<strong>and</strong> 97<strong>Change</strong>s in downstream areas 98Environmental problems 1018. CONCLUSIONS AND RECOMMENDATIONS 103REFERENCES 107APPENDIX 113

ACKNOWLEDGEMENTSThe project was sponsored by Ministry of Environment <strong>and</strong> Forests, NewDelhi. We wish to place on record our sincere thanks to Dr. R.Gnanaharan, Director <strong>and</strong> Dr. J.K. Sharma, former Director, KeralaForest Research Institute for kind support <strong>and</strong> encouragement. We arealso placing on record our sincere gratitude to Shri. Ashok Bhatia,Additional Director, Ministry of Environment <strong>and</strong> Forests, who washelpful during the project period. We express our sincere thanks to Dr.K.C. Chacko, Dr. S.Sankar, <strong>and</strong> Dr. M.P.Sujatha of the Institute foreditorial scrutiny. We are extremely thankful to Mr. John P. Inchakalody,Mr. P. Muhammed Rasheed <strong>and</strong> Ms. U.V. Deepa, Research Fellows whocollected data for the study. We are grateful to Dr.Jagdish Krishnaswamy(ATREE) <strong>and</strong> Dr. S. Sankar for useful suggestions during the initial stagesof the project. The help rendered by Dr. K. Sreelakshmi <strong>and</strong> Dr. V. Anithadeserves special thanks. Thanks are also due to our colleagues in theInstitute who offered comments at the time of presentation of the resultsof the study.

ABSTRACTDegradation of watersheds is one of the major problems in Kerala, whichhas brought about ineffaceable <strong>and</strong> irreversible l<strong>and</strong>use <strong>and</strong> ecologicalchanges, leading to impairment of <strong>its</strong> hydrological functions. Unscientificl<strong>and</strong>use <strong>and</strong> cropping pattern changes in a watershed often causeproblems in water conservation both in upl<strong>and</strong> <strong>and</strong> downstream areas.This accelerates the run­off rate <strong>and</strong> soil erosion <strong>and</strong> alters stream flowquality <strong>and</strong> quantity, which in turn affect onsite production <strong>and</strong>/or offsiteproduction or consumption. In a watershed both upl<strong>and</strong> <strong>and</strong> downstream areas are closely interlinked. However, the nature <strong>and</strong> extent oftheir interlinkage, especially in a forested watershed has not been studiedin depth in Kerala. This study is a modest attempt to fill this gap.Manali watershed of Karuvannur River Basin, where a major part of theforest area of the basin is located, was selected for detailed study. Thebroad objective was to examine l<strong>and</strong>use change <strong>and</strong> <strong>its</strong> effects on ecohydrology<strong>and</strong> socio­economic conditions of the people in the study area.Specific attempts were made to study the nature, extent <strong>and</strong> socioeconomicfactors affecting l<strong>and</strong>use changes <strong>and</strong> forest degradation <strong>and</strong> <strong>its</strong>effects on sediment production <strong>and</strong> water discharge rates <strong>and</strong> onsite <strong>and</strong>off­site agricultural production. Assessment of surface run­off <strong>and</strong> streamflow from watersheds, economic value of water resource, surface wateruse pattern, pricing <strong>and</strong> use conflict over water resources among differentsections in the society was also made. Further it examined linkagesbetween ecological <strong>and</strong> socio­economic systems of the upl<strong>and</strong> <strong>and</strong>downstream areas of the watershed in determining overall development.A nested catchment approach was used to select upstream <strong>and</strong> downstream areas of the watershed. Based on the elevation data, the river basin,with several micro watershed, has been divided into upstream <strong>and</strong>downstream watersheds. One micro watershed, representative of theupstream catchment (Olakara) <strong>and</strong> another from the downstream catchment(Kavallur) have been chosen for detailed monitoring <strong>and</strong> studies.i

The study indicated that there were l<strong>and</strong>use changes, particularlyconversion of forest l<strong>and</strong> to agricultural l<strong>and</strong> in the study area during theanalysis period 1960­61 to 2004­05. For instance, during 1996­2004,area under agriculture increased by 50 per cent, mostly throughconversion of forests. Migration, encroachment, <strong>and</strong> expansion ofagricultural activities were the major socio­economic drivers of l<strong>and</strong>usechanges in the study area. Side by side with conversion of forest l<strong>and</strong> toagricultural fields, there was change in cropping pattern in the studyarea­ from subsistence agriculture to commercial crops. Variation in therelative price of crops was one of the major factors, which influenced thecropping pattern change. Although this change has increased income ofthe farmers, it reduced food security, employment opportunity <strong>and</strong> wateravailability in the study area.There existed more sustained stream flow in forested watershed ascompared to agricultural watershed. The upl<strong>and</strong> areas where plantdiversity was more, was prone to seasonal fire in the past, indicating thedegradation. Sedimentation was low in forested watershed, while it washigh in the upper part of downstream areas. Degradation of forests <strong>and</strong>frequent crop shifts in upl<strong>and</strong> areas resulted in sedimentation in PeechiDam (annually 0.9%). The study suggested the need for undertakingconservation <strong>and</strong> afforestation measures in the degraded forest areas forbetter availability of water.Since water is a naturally existing <strong>and</strong> freely available commodity, mostpeople do not attach any value to it. Therefore, total economic valuationof the Peechi wet l<strong>and</strong> was attempted. Per hectare economic value ofPeechi wet l<strong>and</strong> was found to be Rs.146,039/­. Willingness to pay forregular <strong>and</strong> steady supply of water from Peechi reservoir was alsoassessed. About 80 per cent of the people, who use drinking water fromPeechi, were willing to pay more for timely <strong>and</strong> regular supply of waterwhereas 20 per cent agreed with the existing price.ii

There was conflict over water resources from Peechi Dam among farmers,between farmers <strong>and</strong> users of drinking water <strong>and</strong> between urban dwellers<strong>and</strong> villagers. This was due to increase in dem<strong>and</strong> <strong>and</strong> inefficientmanagement. There existed a close interaction between upl<strong>and</strong> <strong>and</strong> downstream areas of the watershed <strong>and</strong> also between watershed <strong>and</strong> marketshed (dem<strong>and</strong>, supply, price, among others). Further, bio­physical <strong>and</strong>socio­economic factors in upl<strong>and</strong> <strong>and</strong> down stream areas were alsointerlinked. They may be taken into account while implementing anywatershed projects.The study also suggested to undertake proper pricing of water from theDam to generate more funds to meet cost of supply <strong>and</strong> water resourcedevelopment. Promotion of integrated watershed development programmesthrough effective participation of local people for preventing furtherecological degradation in the study areas was also suggested.iii

Chapter 1INTRODUCTIONForests are known to bestow a variety of benef<strong>its</strong> to the society. Inaddition to the customary ecological, economic <strong>and</strong> social benef<strong>its</strong>, forestsprotect water resources, reduce run­off, abate floods, control soil erosion<strong>and</strong> improve water quality. It is widely accepted that, since independence,there has been a rapid decline of area under <strong>and</strong>/or quality of the forestsin most parts of India (Rawat <strong>and</strong> Rawat, 1994). This was consequentialto a variety of factors, of which policies of the successive governments,shortfalls in the implementation of forest development programmes <strong>and</strong>increased activities due to population pressure. Deforestation has resultedin ineffaceable <strong>and</strong> irreversible l<strong>and</strong>use <strong>and</strong> ecological changes, impairingthe hydrologic response <strong>and</strong>/or watershed functions of most forests (Lal,1996). Further, the unsustainable exploitation of the forest ecosystem isdetrimental to the other ecosystems embedded in it viz., forestedwetl<strong>and</strong>s, man­made wetl<strong>and</strong>s <strong>and</strong> also adjacent agricultural system. Inother words, the forest ecosystem <strong>and</strong> the other ecosystems embedded init <strong>and</strong> nearby agricultural ecosystem are closely related <strong>and</strong> theinterlinkages among these ecosystems are so interdependent that, thechange in one ecosystem directly affects the other ecosystems.Water conservation functions of the forests have not been adequatelyemphasized while managing forests, particularly in Kerala (Kallarackal,2000). It is well known that a large number of socio­economic <strong>and</strong>ecological factors affect water­yielding functions of forest areas. To bemore precise, because of the population increase <strong>and</strong> l<strong>and</strong> hunger, mostof the forest areas or upl<strong>and</strong> watersheds in the State have experiencedincreasing levels of encroachment. Plantation activities in the upl<strong>and</strong>areas brought about l<strong>and</strong>use changes that caused ecosystem alterations<strong>and</strong> soil erosion. Similarly, changes in the cropping pattern, soil erosion<strong>and</strong> sedimentation in the down stream areas also lead to changes inecology <strong>and</strong> agricultural production.1

The pertinent questions are: what are the reasons for l<strong>and</strong>use changes inupl<strong>and</strong> areas <strong>and</strong> how do they consummate in ecosystem <strong>and</strong> economicchanges which in turn adversely affect water conservation/yield? A varietyof factors such as population increase <strong>and</strong> implementation of extravagantgovernment policies (Grow More Food Programme, for example) hadresulted in changes in l<strong>and</strong>use in the past. When the market economybegan to play the primary role, alteration in marketshed (parallel towatershed) started to influence the changes in watershed. For example, adrastic change in price of a crop is often followed by a crop shift in thewatershed. Similarly a change in the production of crops also affects themarket shed. This inter­relationship is more powerful in the currenteconomy, especially with the recent liberalization policies, in the contextof globalization. Unscientific l<strong>and</strong>use practices often cause problems in insitu water conservation, as water holding <strong>and</strong> infiltration capacity of thesoil are adversely affected. <strong>L<strong>and</strong></strong>scape transformation caused by forestdisturbance is predicted to have dramatic effect on run­off rate, soil erosion,stream flow <strong>and</strong> quality <strong>and</strong> quantity of water which in turn affect onsite<strong>and</strong>/or off­site production or consumption (Bisht <strong>and</strong> Tiwari, 1996).In the context of vagaries of monsoon, the burgeoning drought situation,<strong>and</strong> augmenting water resource availability both for drinking <strong>and</strong>irrigation purposes, research on hydrological functions of forest assumescolossal importance. The benefit of irrigation <strong>and</strong> drinking water, at asubsidized rate, is largely restricted to the urban <strong>and</strong> suburban areas <strong>and</strong>seldom reaches the rural poor. This necessitated undertaking more studies,particularly micro level studies linking l<strong>and</strong>use changes, forests <strong>and</strong> waterresources. Keeping this in view, a detailed study was undertaken in theManali watershed of Karuvannur river basin in Thrissur district, Kerala.1.1 The study areaThe Karuvannur river basin lies between 10 0 15’ to 10 0 40’ North latitude<strong>and</strong> 76 0 00’ to 76 0 35’ East longitude within Thrissur <strong>and</strong> Western2

Boundary of Palakkad districts of Kerala (Fig.1.1). It is bounded byThrissur <strong>and</strong> Chavakkad Taluks of Thrissur district in the North,Mukundapuram <strong>and</strong> Kodungallur Taluks of Thrissur district in theSouth, Alathur <strong>and</strong> Chittor Taluks of Palakkad district in the East <strong>and</strong>the Arabian Sea in the West. Karuvannur River basin, constituting anarea of 1054 km 2 , lies in Southern Western Ghats <strong>and</strong> covers 32panchayats, 9 blocks <strong>and</strong> 2 districts. The river originates from theWestern Ghats <strong>and</strong> is fed by <strong>its</strong> two main tributaries, viz., the Manali <strong>and</strong>the Kurumali. The Manali river originates from Ponmudi in the boundaryof Thrissur <strong>and</strong> Palakkad districts at an elevation of + 928 m. TheChimony <strong>and</strong> Muply, the two sub­tributaries of the Kurumali originatefrom Pundimudi at an elevation of + 1116 m. This is one of the major riverbasins with the actual utilizable water resources of 623 Mm 3 of which thenet utilizable surface <strong>and</strong> ground water resources are 519.8 Mm 3 <strong>and</strong>103.2 Mm 3 respectively. Karuvannur river has a drainage area of 1054km 2 , stream length 48 km, average monsoon flow of 1275 Mm 3 , averagelean flow 55 Mm 3 <strong>and</strong> total flow 1330 Mm 3 . (Rajagopalan <strong>and</strong> Sushanth,2001). The average rainfall in the low l<strong>and</strong> of the river basin wasestimated to be 2858 mm, the midl<strong>and</strong> 3011mm <strong>and</strong> the highl<strong>and</strong> 2851mm. About 60 per cent of the rainfall is received during south westmonsoon period, 30 per cent from north east monsoon <strong>and</strong> 10 per cent inthe pre­monsoon period.Manali is one of the important sub­watershed systems in the river basin.This is also one of the important forest areas of the river basin as well asthe district. Keeping the above facts in mind, Manali sub­watershed wasselected for detailed study. Total area of this watershed is 274 km 2 <strong>and</strong>lies in Thrissur district of Kerala (Fig.1.1). It is spread over 13 villages,constituting a little over of 11 per cent of the total area of the district(3032 km 2 ). The utilizable annual surface water is 40.6 per cent of theavailable annual surface water <strong>and</strong> 25.5 per cent of the mean annualrainfall. The available annual surface water (mean runoff) is 62.8 per centof the mean annual rainfall (Rajagopalan <strong>and</strong> Sushanth, 2001).3

Fig.1.1 Location map of Karuvannur River Basin4

1.2 Ecological <strong>and</strong> economic problems in the study areaMajor forest areas of the watershed are concentrated at Peechi region ofPeechi­ Vazhani Wildlife Sanctuary which was established in 1958,constituting an area of 76.5 km 2 . Evergreen, semi­evergreen, moistdeciduous <strong>and</strong> scrub types of forests are the main vegetation types ofwhich the first three account for 22, 17 <strong>and</strong> 28 per cent respectively.Owing to inadequate protection/conservation effort, this WildlifeSanctuary is characterized by high degradation levels <strong>and</strong> low density ofwildlife. Of the total forest area, highly <strong>and</strong> moderately degraded areasaccount for 14 <strong>and</strong> 16 per cent respectively (Deepa, 2000). PeechiReservoir is located in the watershed which supplies major share of theirrigation <strong>and</strong> drinking water in Thrissur district.Forest dwelling tribes were the early inhabitants of this area <strong>and</strong>depended up on collection of non­timber forest products (NTFPs) for theirlivelihood. Influx of settlers to this area can be traced back to early 1950’sat the time of construction of Peechi dam across the Manali river <strong>and</strong>encroachment has been further accentuated in the subsequent years. Thesettlers are mostly agriculturists who cultivate a variety of crops such asvegetables, banana, rice, tapioca, cashew, rubber, etc. Ownership rightsof many settlers are undecided. People (tribal <strong>and</strong> other localcommunities) living immediately around the natural forests are highlydependent on the forests for agriculture, NTFPs, firewood, cattle grazing<strong>and</strong> small construction needs, resulting in degradation of forest areas. Inother words, the degradation of forest was caused by biotic pressuressuch as illicit cutting, grazing, fire, etc. which are anthropogenic in origin.This has resulted in structural <strong>and</strong> other changes in the forest, includinginadequate regeneration (Swarupan<strong>and</strong>an <strong>and</strong> Sasidharan, 1992).Our pilot survey indicated that there have been significant changes in thel<strong>and</strong>use which have had adverse effects on forest ecology, water yield, dryseason flow, soil erosion, stream sediment load, etc. <strong>and</strong> agriculturalproduction. Originally, the Peechi Irrigation Project was aimed at5

supplying irrigation water to agricultural sector, including Kole l<strong>and</strong>s. Butdue to urbanisation <strong>and</strong> the influence of the well­to­do people in thedistrict, more water has been diverted for drinking purpose. This in turnhas brought about two major changes in the economy. First, with thedecrease of supply through irrigation canal, especially during summerseason, the water tables in the well in the study area has gone down,resulting in shortage of water. Secondly, in the absence of adequateirrigation water supply, particularly in the mid <strong>and</strong> tail end regions of thecanals, the productivity of the crops have been declined which in turnadversely affected food security <strong>and</strong> income levels of the people.The area under crops in the watershed <strong>and</strong> also other irrigated areas inthe district have significantly declined over a period of time. The dem<strong>and</strong>of water for irrigation, drinking, industrial <strong>and</strong> other common needs ismuch higher than the supply. There is no reliable information regardingdem<strong>and</strong>­supply gap of water resources in Manali watershed. However, inthe Karuvannur River Basin, where this watershed is located, the deficit isexpected to be 22 Mm 3 in rabi season <strong>and</strong> 151 Mm 3 in summer season(Rajagopalan <strong>and</strong> Sushanth, 2001) indicating that water shortage is verysevere during summer. The drinking water supply from Peechi Reservoiris estimated to be 50.5 Mm 3 per day which meets a good part of the waterrequirements of the urban <strong>and</strong> semi­urban areas of the district, but notthat of villages.The sustainability in the resource use is imperative for better livelihoodopportunities, environmental balance <strong>and</strong> rural development. Further, thebiophysical <strong>and</strong> socio­economic linkages between the upl<strong>and</strong> <strong>and</strong>downstream areas of a watershed <strong>and</strong> <strong>its</strong> influence on overall economicdevelopment have been widely accepted (James et al., 2000). The changesin the upl<strong>and</strong> areas have their own impact on downstream, as both areclosely interlinked. For instance, soil erosion is a natural process but it getsaccelerated due to excessive anthropogenic activities <strong>and</strong> <strong>its</strong> implicationsare mostly economic, affecting welfare of the society (Kumar, 2000). Soil6

erosion has both onsite (direct) <strong>and</strong> off­site (indirect) impacts which affectproductivity of the upl<strong>and</strong> areas <strong>and</strong> economic activities in thedownstream area. It also imposes economic <strong>and</strong> environmental costs onpeople living in both the regions, which ultimately affect theirdevelopment. This requires a comprehensive environmental auditing ofsoil, water <strong>and</strong> production loss arising from l<strong>and</strong>use change in awatershed. This study is a modest attempt in this line.1.3 ObjectivesThe broad objective of this study is to examine l<strong>and</strong>use change <strong>and</strong> <strong>its</strong>effects on eco­hydrology <strong>and</strong> socio­economic conditions of the people inthe study area. Specific attempts were made to:1. Study the nature <strong>and</strong> extent of l<strong>and</strong>use <strong>and</strong> cropping pattern changes<strong>and</strong> important socio­economic drivers affecting it.2. Examine the effects of l<strong>and</strong>use on hydrology­ run­off, stream flow,ground water table, temperature <strong>and</strong> humidity­ in the watershed3. Analyze the effects of l<strong>and</strong>use/cropping pattern changes on vegetation,sedimentation, agricultural production <strong>and</strong> socio­economic conditionsof the people4. Assess economic value of water resource, surface water use pattern,pricing <strong>and</strong> use conflict over water resources among different sectionsin the society5. Examine the linkages between ecological <strong>and</strong> socio­economic systemsof the upl<strong>and</strong> <strong>and</strong> downstream areas of the watershed in determiningoverall development.7

Chapter 2METHODOLOGYBroadly, the study examines selected biophysical <strong>and</strong> socio­economicaspects of the problem <strong>and</strong> integrates them to underst<strong>and</strong> theirimplications in the development perspective. The methods employed tostudy major aspects of the problems are given below.2.1 Selection of micro watershedsA nested catchment approach has been followed in the selection of amicro watershed considering the large area covered by the KaruvannurRiver Basin. The river basin, with several micro watersheds, has beendivided into upstream <strong>and</strong> downstream watershed, based on the elevationdata. One micro watershed, representative of the upstream catchment(Olakara) <strong>and</strong> another from the downstream catchment (Kavallur) havebeen chosen for detailed study.2.2 <strong>L<strong>and</strong></strong> use dynamicsSatellite data productsSatellite data products on 1:250,000 scale (hardcopy) <strong>and</strong> digital data ofIRS1C LISS III/IRS1D LISS III of January 1996 <strong>and</strong> IRS P6 (PAN+LISS3merged product) of January 2004 were used in the present study.Ancillary dataThe following ancillary data were used directly or indirectly for the studypurpose.i. Survey of India topo­sheets on 1:250,000 <strong>and</strong> 1:50,000 scales.ii. Forest type maps of India (Champion <strong>and</strong> Seth, 1968)iii. Biogeographical map (Rodgers <strong>and</strong> Panwar, 1988)9

iv. Management maps/Stock maps of State Forest Departmentv. Forest Vegetation maps on 1:250,000 scales <strong>and</strong> 1:50,000 scaleavailable with Forest Survey of India for Forest density layer <strong>and</strong>other relevant information as base details.2.3 Vegetation classification schemeIn the present study, Level II vegetation classification is attempted.Following classification scheme was adopted for stratification, usingRemote Sensing Digital data.Forest VegetationI. Forests1. Dominant phenological types1.1. Evergreen1.2. Semi­evergreen1.3. Moist deciduous1.4. Dry deciduous2. Gregarious types (single species dominated)2.1. Bamboo3. Local specific classes3.1. Mangrove3.2. Sholas3.3. Riverian3.4. Sacred groves4. Degradation types4.1. Degraded forest stages (eg.10­40 per cent tree density, signsof erosion <strong>and</strong> composition are not confirming with any of theabove types).10

II.III.ScrubsGrassl<strong>and</strong>sNon­forest vegetationIV.Major Wetl<strong>and</strong>sV. Plantation (Tea/Coffee/Coconut gardens etc.)VI.AgricultureVII. Fallow/BarrenVIII. Water bodyIX.Settlement2.4 Digital classification of satellite dataPre­processing: The raw digital data was enhanced using contraststretching or ratio based techniques to facilitate better discriminationduring ground data collection or locating sample points.Reconnaissance survey: The reconnaissance survey was undertaken forgetting better acquaintance with the general nature of vegetation of thearea. Major vegetation types <strong>and</strong> few prime localities of characteristictypes were noted during reconnaissance survey. The variations <strong>and</strong> tonalpatterns were also observed on existing images/maps. Traversing alongmajor drainage, roads, paths, etc. for ground truthing, existing literaturesurvey, <strong>and</strong> interaction with forest officials were also made during fieldsurvey.2.5 Vegetation characterization using satellite dataSatellite data in digital form were analysed to characterize the vegetationusing interactive digital analysis procedures. The preparation ofvegetation map assumes a critical step in the vegetation characterizationprocedure.11

The study area falls in a single satellite scene. The scene wasgeometrically corrected with reference to Survey of India 1: 50,000 scaledTopo­sheets. The Vegetation classification was performed as per thescheme mentioned earlier. The different scene was classified usingMaximum likelihood method. After complete classification, misclassifiedareas were checked <strong>and</strong> reclassified considering small Area of Interest(AOI) or through interactive editing for improved accuracy. Finally theclassified sub­scenes were mosaiced <strong>and</strong> the edges were smoothened. Theapproach for l<strong>and</strong> cover mapping is as follows:Raw Satellite DataPre­processingGeometric <strong>and</strong> radiometriccorrectionSun angle effectHaze removalRationingNDVI etc. Removal of (Histogram minimizationdiscrepancies Dark object subtraction etc.)Knowledge base Hybrid classification Ground truthingDigitally classified vegetation/cover map2.6 Accuracy evaluationThe classification performance was evaluated by redundant training areas<strong>and</strong> field sample points based on the commission <strong>and</strong> omission errormatrix <strong>and</strong> hence overall classification accuracy was calculated. It shouldbe noted that overall classification accuracy is more than 85 per cent.12

Phytosociological data CollectionPhytosociological analysis provides the real meaning to any biodiversity<strong>and</strong> vegetation analysis by quantifying the structural parameters of thecommunities. The sampling principle was based on inventorying thehomogeneous strata identified by remote sensing data analysis. Accordingto the spectral signature variability in consonance with the vegetationtype <strong>and</strong> orientation of terrain, sample points were marked on 1: 50,000scale SOI toposheets in the study area. The plot size in the sample pointswas of 33 m x 33 m covering approximately an area of 0.1 hectare.Taxonomical census of each plot as well as menstruation of individualwoody members qualifying as tree <strong>and</strong> shrub yielded the data essential forarriving structural status.Sampling strategyStratified r<strong>and</strong>om sampling with probability proportion to the size (PPS)was adopted for analysing vegetation composition of all the typesencountered. To sample an area of nearly 0.01 per cent of total area ofeach type, percentage sampling procedure was adopted. In view of thetime, money <strong>and</strong> availability of other resources, optimum number ofsample points has been taken up, covering all vegetation type, in differentdensity/disturbance regimes.For each vegetation type, the size of the quadrat was determined through‘Species­Area curve method’ (Muller – Dombois <strong>and</strong> Ellenberg, 1978). Theplot size was restricted to 0.1 ha. (32 m x 32 m). A minimum of 8­10quadrats were analysed for each vegetation type.Marking location of sample plotsEach sample site was located on survey of India toposheets. Exactlongitude <strong>and</strong> latitude <strong>and</strong> location height (msl) were noted down usingGlobal Position System (Garmin III plus <strong>and</strong> Trimble GeoXT).13

Creation of watershed boundaries <strong>and</strong> masksThe precise watershed boundaries as obtained from Survey of Indiatoposheets were used <strong>and</strong> the bit map was created to use them aswatershed mask. It was ensured that the SOI watershed boundaries areproperly registered on the geometrically corrected image <strong>and</strong> georeferencedmap.Plot method <strong>and</strong> enumerationAt each sample plot, complete enumerations of species were done. Thecircumferences at breast height (cbh) or 1.3 m above ground level, of alltree species were recorded. The individuals with cbh >30 cm wereconsidered as tree <strong>and</strong> with >17 cm <strong>and</strong>

Total number of quadrats in which species occurredFrequency = _______________________________________________ X 100Total number of quadrats studiedTotal number of individuals of the speciesDensity = __________________________________________ X 100(per quadrat) Total number of quadrats studiedTotal number of individuals of species occurringAbundance = _______________________________________________ X 100Total number of quadrats in which species occurredFrequency of a speciesRelative frequency = __________________________ X 100Sum of frequency of all speciesRelative density = Density of a species___________________________ X 100Sum of density of all speciesRelative dominance =Total st<strong>and</strong> basal cover of species___________________________________ X 100Total st<strong>and</strong> basal cover of all the speciesBasal cover = (cbh) 2______4 IISum of basal cover of individual plants of a species will yield total st<strong>and</strong>basal cover of that species.Importance Value Index (IVI) = Relative Frequency + Relative Density +Relative DominancePlant diversityThe plants were enumerated by line transect method. Three enumerationsin the months of January, March <strong>and</strong> October were carried out to have arepresentation of plants occurring in different seasons of the year. Plantswere mostly identified in the field during enumeration. Species which15

could not be identified in the field were brought to the Institute <strong>and</strong>identified with the literature (Sasidharan <strong>and</strong> Sivarajan, 1996) <strong>and</strong> bycomparing with authentic herbarium specimens in the Kerala ForestResearch Institute Herbarium.2.7 Hydro meteorological observationsHistorical data on rainfall <strong>and</strong> stream flow data for the last few years,sometimes as early as 1963 were collected from the HydrologyDepartment, Government of Kerala.Rainfall distribution during study periodTipping bucket rain gauges (Onset Computer Corporation, USA) wereinstalled <strong>and</strong> daily data from January 2005 till December 2006 wererecorded at both watersheds of Olakara <strong>and</strong> Kavallur.Stream flow measurementThree streams were identified in both the watersheds for measurement.Daily measurements for the flow were taken. Flow measurement wastaken using velocity float method. The depth of the flow through the outletwas measured twice a day at 8.00 a.m. <strong>and</strong> 2.30 p.m.Velocity float methodIn the velocity float method, discharge rate was computed using theformula,Q=AV= (bd) L/twhere, Q = Discharge rate (m 3 /sec)A = Area of cross section of flow (m 2 )V = Velocity of flow (m/sec)d = Depth of flow (m)b = Width of flow (m)t = Time taken by the float (sec) to travel specified distance in m16

Depth of flow <strong>and</strong> time taken by the float to reach the length were notedeveryday. Velocity was calculated. By multiplying velocity with area of flowthe discharge was measured.At Olakara, three streams were monitored in the micro watershed forstream flow. All the three streams were flowing through forested areas. AtKavallur also, three streams were monitored:Stream 1 Originating <strong>and</strong> flowing through a felled Eucalyptus plantationStream 2 Originating from a forest <strong>and</strong> flowing through plantation whichis planted under social forestry projectStream 3 Originating <strong>and</strong> flowing through agricultural l<strong>and</strong>2.8 Water table fluctuation studiesTen wells from each micro watershed were selected for the water tablefluctuation studies. Observation regarding the water level was taken at 15days interval. The depth of water table was taken as the depth from theground level to top of water level in the well. Fluctuations were calculated<strong>and</strong> depicted in the graphical form.Relative humidity <strong>and</strong> temperatureData loggers (Gemini Tiny tag data loggers, UK) for measuring dailytemperature <strong>and</strong> relative humidity (with thermistor <strong>and</strong> humicap sensors)were installed at both watersheds. Hourly data were recorded.Ground water table observationOpen dug wells are basic groundwater source for both sites. Based on thephysical survey carried out, 11 open wells were selected for ground watertable studies from Kavallur <strong>and</strong> 8 from Olakara. Kavallur area comprisesof paddy fields, coconut, banana, vegetables <strong>and</strong> rubber plantations. Allthe wells selected in Olakara were located within the forest area. Datawere collected fortnightly using a measuring tape.17

Soil physico­chemical propertiesTwenty­five plots of 33 m x 33 m size were laid out in the experimentalarea at Olakara. In each plot, three soil p<strong>its</strong> of 60 cm x 60 cm x 30 cmdimensions were taken <strong>and</strong> soils collected from 0­20 cm, 20­40 cm <strong>and</strong>40­60 cm depths. The soils from three p<strong>its</strong> of the same depth were mixed<strong>and</strong> made into a composite sample. The samples were air dried <strong>and</strong>processed for determination of gravel, particle­size separates, bulkdensity, maximum water holding capacity, pH <strong>and</strong> organic carbon.In six plots at Olakara, locally fabricated sediment collectors wereinstalled. The sediments were collected at periodic intervals in July,August <strong>and</strong> October 2005 <strong>and</strong> June, August <strong>and</strong> September 2006. Thecollected sediments were quantified <strong>and</strong> the nutrient contents (Nitrogen,Phosphorus <strong>and</strong> Potassium) were found out. Attempts were also made toassess sediment yield in the Kavallur area. Unfortunately no data couldbe collected as the sediment collectors installed in the field weredestroyed.2.9 Socio­economic aspectsSocio­economicsThe socio­economic part of the study is based on both primary <strong>and</strong>secondary data. The primary data were gathered from a sample ofhouseholds. The study area was spread over 13 villages (Marakkal,Vaniyampara, Chuvannmannu, Pattikkad, Kannara, Peechi,Maniyankinaru, Olakara, Kavallur, Puttur, Nadathara, Manamangalam,<strong>and</strong> Pudukkad) in Trichur taluk of which six villages, that is, three eachfrom upl<strong>and</strong> <strong>and</strong> downstream areas were selected at r<strong>and</strong>om for primarydata collection. Data were collected from 100 households located in theselected villages. Primary data were gathered from 100 farmers in theupl<strong>and</strong> <strong>and</strong> downstream areas using multi­stage stratified r<strong>and</strong>omsampling technique. The time series data relating to change in the18

economic variables such as production, price <strong>and</strong> cropping pattern, etc.were gathered from secondary sources viz., publications of the StatePlanning Board, <strong>and</strong> Kerala State <strong>L<strong>and</strong></strong> <strong>Use</strong> Board. Historical data weregathered from age­old people in the study area.2.10 Economic valuation of water resourcesIn the study area, the reservoir is used for supplying water for irrigation<strong>and</strong> drinking purposes, fishing, ecotourism <strong>and</strong> education <strong>and</strong> research.It also gives a number of functional benef<strong>its</strong> such as increasingagricultural productivity, soil conservation, recharging of ground water<strong>and</strong> regulation of stream flows. Thus, value of the water resources mightbe much higher than one generally perceives. An attempt was made toestimate market <strong>and</strong> non­ market benef<strong>its</strong> of the water resources in thePeechi Reservoir in the total economic value framework.Total economic value of Peechi­wetl<strong>and</strong>s was undertaken using thest<strong>and</strong>ard tools for valuation of ecosystem. Munasinghe (1992) hasclassified of the major categories of value assigned to nature (Fig.2.1).This was used as an analytical tool to determine the main valuesassociated with the functions of the wetl<strong>and</strong>s <strong>and</strong> to identify suitablevaluation tools to assess their monetary value. Munasinghe (1992) dividedthe total economic value of nature into use <strong>and</strong> non­use values. The usevalues are divided into the direct <strong>and</strong> indirect use values <strong>and</strong> optionvalues. The non­use values are divided into existence <strong>and</strong> bequest values.The TEV is embedded in the total value concept, which is detailed in thefollowing section.Total valueThe total value (TV) of an ecosystem is the sum of two components: aprimary value (PV) <strong>and</strong> a secondary value (SV).TV = PV + SV (1)19

Primary valueThe Primary value (PV) or 'glue' value or 'intrinsic' value is not associatedwith the ecosystem's use, but is beyond <strong>its</strong> value to humans (Turner etal., 1994). The PV is rather perceived as a non­ anthropocentric or'ecocentric' value which is inherent to the ecosystem's self organizingcapacity, <strong>and</strong> hence to <strong>its</strong> existence <strong>and</strong> continuity, independently ofhuman preferences, <strong>and</strong> irrespective of human desires or will.Total Economic Value<strong>Use</strong> valuesNon use valuesDirect usevaluesIndirect usevaluesOptionvaluesBequestvaluesExistencevaluesOutputs thatcan beconsumeddirectlyFunctionalbenef<strong>its</strong>Future direct<strong>and</strong> indirectuse valuesValues ofleaving use<strong>and</strong> non usevalues foroffspringValue fromknowledgeofcontinuedexistence,based one.g. moralValues offunctionsrelated to:¨ Food¨ Biomass¨ Recreation¨ HealthValues offunctionsrelated to:¨Ecologicalfunctions¨Floodcontrol¨StormprotectionValues offunctionsrelated to:¨ Biodiversity¨ ConservedhabitatsValues offunctionsrelated to:¨ Habitats¨ Irreversible changesValues offunctionsrelated to:¨ Habitats¨ EndangeredspeciesFig. 2.1 Classification of total economic value, (Source: Munasinghe, 1992)20

Secondary valueThe secondary value (SV) or 'instrumental' value or 'economic' value israther an anthropocentric, utilitarian value, which fully relies on humanself­interest, <strong>and</strong> is derived only from individual preferences. It is equal tothe total worth of the ecosystem's goods <strong>and</strong> services provided for theindividual. It is the commonly known concept developed by the economicscience (Pearce, 1999), called total economic value (TEV), <strong>and</strong> consistingof use values (UV) which include direct use values (DUV), indirect usevalues (IUV) <strong>and</strong> option values (OV) <strong>and</strong> non­use values (NUV) whichinclude existence value (EV) <strong>and</strong> bequest value (BV).SV = UV + NUV (2)UV = DUV + IUV (3)NUV = EV + BV (4)Combining equations (3) <strong>and</strong> (4); EV = (DUV+IUV+OV)+(EV+BV) (5)<strong>Use</strong> valuesAccording to the classification adopted by Turner et al. (1994), the usevalues (UV) are disaggregated into direct use values (DUV), indirect usevalues (IUV) <strong>and</strong> option values (OV).Direct use valueDirect consumptive useThe direct use value (DUV) is broadly determined by the production ofmeasurable <strong>and</strong> merchantable (or at least potentially merchantable)outputs. For wetl<strong>and</strong> ecosystems, DUV is subdivided into consumptivevalues (CV), <strong>and</strong> non­consumptive values (NCV), such as recreation,sightseeing, spiritual use. DUV is practically equal to the net incomegenerated from the ecosystem. For assessing the value of tangible benef<strong>its</strong>viz.,, fish, the following formula was adopted.21

where,nDUV = å ( P i Q i - C i )(6)iP i is the price of product i ,Q i is the amount of product i , being harvested, <strong>and</strong>C i is the cost involved in the harvesting of product i .Direct non­consumptive useThe recreation benef<strong>its</strong>/tourism benef<strong>its</strong> were estimated using travel costmethod (TCM). Travel cost method was applied in the study area forestimating the consumer surplus of the visitors. The dam is under thecontrol of Irrigation Department <strong>and</strong> prior permission is not required forthe same. A nominal entrance fee of Rs 2/­ is charged for the visitors ofdam.The Clawson <strong>and</strong> Knetsch (1966); TCM dem<strong>and</strong> function is of the form:V i = f (P i , X)where,Vi = Visitation rate of i th populationP i = Cost of visiting the site from zone 1X = Vector of socio economic variables affecting travel costdem<strong>and</strong> curveThe individual travel cost method was applied in the study to estimate thedem<strong>and</strong> function. The study adopted a semi log function to estimate thedem<strong>and</strong> function. The consumer surpluses were estimated from thecoefficients obtained from the dem<strong>and</strong> function (Hangley, 1989).The estimated dem<strong>and</strong> function is of the form;V = f (X1, X2, ….X8)where,V =X1 =Number of vis<strong>its</strong> by each visitorResidence of the respondent (local=1, 0 otherwise)22

X 2 = Education (dummy variable)X 3 = Willingness to pay (Rs.)X 4 = Income (Rs. year ­1 )X 5 = Visiting day (weekend=1, weekdays= 0)X 6 = Opportunity cost of time (income corrected for hoursspent at the site (Rs.)X7 =X8 =X 9 =X10 =Travel cost (expenses incurred on travel Rs/person)Distance traveled (km)Infrastructure (dummy variable; improve presentcondition=1; 0 otherwise)Local travel cost (expenses at the site in Rs.)Three basic steps are involved in travel cost models. First, it is necessaryto undertake a survey of a sample of individuals visiting the site todetermine their costs incurred in visiting the site. These costs includetravel time, any financial expenditure involved in getting to <strong>and</strong> from thesite, along with entrance (or parking) fees. In addition, information on theplace of origin for the journey, <strong>and</strong> basic socio­economic factors such asincome <strong>and</strong> education of the individual is required. The resulting data ismanipulated to derive a dem<strong>and</strong> equation for the site. This relates thenumber of vis<strong>its</strong> to the site to the costs per visit. The third step is toderive the value of a change in environmental conditions. For this, it isnecessary to determine how willingness to pay for what the site has tooffer alters with changes in the features of the site. The domestic touristsfrequented the site while foreigners visited very rarely or occasionally.Hence dem<strong>and</strong> function was estimated for only domestic tourists.Indirect use valuesThe indirect use values (IUV) are derived basically from the functionalservices provided by the ecosystem to support current production <strong>and</strong>consumption (eg. hydrological cycle stability, natural filtration of pollutedwater, climate regulation, recycling of nutrients, biodiversity, etc.).23

Option valuesContrary to direct <strong>and</strong> indirect use values which refer to (potential)effective use of the ecosystem's goods <strong>and</strong> services by humans at present,the option value (OV) refers to option of a potential use of these goods <strong>and</strong>services, by people themselves or by future generations. In the context ofOV, people preserve ecosystem functions for possible use in the future, evenif others will use them.Non­use valuesThe concept of non­use values (NUVs) is more complicated to define <strong>and</strong>measure; they are also referred to as 'passive' use values; they are notassociated with actual ecosystem’s use, or even with the alternative to usea good or service. According to the classification adopted by Turner et al.(1994), NUVs are disaggregated into existence value (EV) <strong>and</strong> bequestvalue (BV).Existence value <strong>and</strong> bequest valueThe existence value (EV) is the satisfaction value derived by individualsfrom the pure fact that an ecosystem <strong>and</strong>/or <strong>its</strong> constituents exist, fortheir own, regardless of necessarily seeing it or having any intention ofusing it directly (Turner et al., 1994). The bequest value (BV) is perceivedas the moral value people derive from knowing that an ecosystem <strong>and</strong>/or<strong>its</strong> constituents will be passed on to future generations to enjoy it.Contingent valuation methodPrimarily, contingent valuation method was used to know the willingnessto pay. Contingent Valuation (CV) surveys directly ask people what theyare willing to pay for something they value or are willing to receive incompensation for tolerating a cost. Personal valuations for increase ordecrease in the quantity of some goods based on a hypothetical marketare undertaken. The aim is to elicit valuations or bids, which are close to24

what would be revealed if an actual market existed. CV employs aquestionnaire format where respondents are asked how much they wouldbe willing to pay or willing to accept compensation for a specified gain orloss of a given good or service. Economic value estimates yielded by CVsurveys are ‘contingent’ upon the hypothetical market situation that ispresented to respondents <strong>and</strong> allows them to trade off gains <strong>and</strong> lossesagainst money. WTP/WTA questions may be asked in a number of ways,including open­ended, where the respondent states their maximumWTP/WTA, <strong>and</strong> dichotomous choice, where the respondent is required toanswer yes or no to a ‘bid’.Simple CVM exercises can be based on the “open ended” elicitationformats, where the individual is simply asked to state his/her maximumWTP or minimum WTA for a given environmental change. However, thisapproach becomes biased when the respondent state a WTP/WTA lower orhigher than the true one in order to influence the decision making processfor the sake of his own profit. To avoid the drawbacks of open – endedformat, an iterative technique called the “bidding game” is used. In thistechnique the respondent is asked whether he accepts to pay a givenamount of money. If he refuses, the proposed amount is reduced(increased) by a given percentage (say 10%). The procedure is repeateduntil the respondent answers “yes”. The penultimate amount is taken ashis maximum WTP (minimum WTA) for obtaining (to give up) theenvironmental improvement. If the individual accepts the proposedamount is increased (decreased) of say 10 per cent. The procedurecontinues until the individual answers “no”. Here also the last amountproposed is taken as his maximum WTP (minimum WTA) for obtaining (togive up) the environmental improvement. Some of the data relating topricing of water have been drawn from studies carried out in the studyarea recently (Sreelakshmi, 2005)The stakeholders of Peechi wetl<strong>and</strong>s were classified into three, viz.,drinking water users, irrigation users <strong>and</strong> fishermen for the purpose ofthe study. Data were gathered from 120 drinking water users, 27025

irrigation users <strong>and</strong> 50 fishermen who catch fish from Peechi reservoir.Primary data collected from the farmers <strong>and</strong> those who use drinking waterwere used to study water use efficiency <strong>and</strong> use conflict. Data collectedfrom 500 tourists were used for estimation of recreation value.The study also made use of relevant secondary data collected from the 20respective village offices, forest range offices, Irrigation Department <strong>and</strong>office of the Kerala Water Authority.26

Chapter 3LAND USE AND CROPPING PATTERN CHANGESThe extent, magnitude <strong>and</strong> intensity of l<strong>and</strong> use <strong>and</strong> <strong>its</strong> resultant changesin the agricultural sector are discussed in this section. This chapter isorganized <strong>and</strong> presented under three headings viz., l<strong>and</strong> use change,cropping pattern change <strong>and</strong> socio­economic drivers of l<strong>and</strong> use <strong>and</strong>cropping pattern changes.3.1 <strong>L<strong>and</strong></strong> use change<strong>L<strong>and</strong></strong> is defined as an area where all human activities are conducted <strong>and</strong>it is also the source of the materials needed for this anthropogenicconduct (Briassoulis, 2000). Human use of l<strong>and</strong> resources gives rise tol<strong>and</strong> use <strong>and</strong> generally, the two broad sets of dynamic factors/forces,which influence the l<strong>and</strong> use, are human needs <strong>and</strong> environmentalfeatures <strong>and</strong> processes. The operations of these forces are continuousresulting in frequent changes in the l<strong>and</strong> uses <strong>and</strong> the magnitude of l<strong>and</strong>use change varies with the time period being examined as well as with thegeographical area. These changes have at times been beneficial <strong>and</strong> attimes caused detrimental impacts or effects. The latter is the chief causeof concern, as they impinge variously on human well­being <strong>and</strong> welfare(Meyer <strong>and</strong> Turner, 1994).The terms l<strong>and</strong> use <strong>and</strong> l<strong>and</strong> cover, though not strictly synonymous, havebeen used inter­changeably worldwide. Therefore, an underst<strong>and</strong>ing ofthe different l<strong>and</strong> related terms assumes significance while taking up anystudy on l<strong>and</strong> use change. <strong>L<strong>and</strong></strong> cover is the biophysical state of earth’ssurface <strong>and</strong> the immediate subsurface (Turner et al., 1995). Originally,the term referred to the type of vegetation that covered the l<strong>and</strong> surface,but has broadened eventually to include human structures, such asbuildings or pavements, <strong>and</strong> other aspects of the physical environment(Moser, 1996). The l<strong>and</strong> use involves both the manner in which thebiophysical attributes of the l<strong>and</strong> are manipulated <strong>and</strong> the intent27

underlying that manipulation­ the purpose for which the l<strong>and</strong> is used(Turner et al., 1994). In other words, l<strong>and</strong> use denotes the humanemployment of l<strong>and</strong> (Turner et al., 1995). In this study, the words l<strong>and</strong> cover<strong>and</strong> l<strong>and</strong> use changes are used synonymously <strong>and</strong> the same is analysedon a watershed level for a period of 44 years i.e. from 1960 to 2004.General classifications of l<strong>and</strong> use followed by Kerala State <strong>L<strong>and</strong></strong> <strong>Use</strong>Board are forest area, l<strong>and</strong> put to non agricultural use, barren l<strong>and</strong>,cultivable waste, cultivable fallow, net area sown, area sown more thanonce <strong>and</strong> total cropped area. The compound growth rates of various l<strong>and</strong>use categories during the period 1960 to 2004 are given in Table 3.1. Thel<strong>and</strong> use categories such as area under forests, barren l<strong>and</strong> <strong>and</strong> areasown more than once <strong>and</strong> total cropped area showed a negative growthrate while the other categories showed a positive trend. Further, allcategories except cultivable fallow showed a deceleration trend, indicatingthat more agricultural l<strong>and</strong>s are put to fallow. In the context of decliningfood production <strong>and</strong> low growth rate of agriculture in the state, this is nota healthy trend.Table 3.1: <strong>L<strong>and</strong></strong> use change over the years: Trend analysis (1960­2004)Variable Trend equation Cgr (%) A/dForest area In FA = 11.8693 ­ 0.00835t ­0.83 D**<strong>L<strong>and</strong></strong> put to nonagri­useIn LPTNAU = 9.4678 + 0.02144t 2.17** D**Barren l<strong>and</strong> In BARAN = 8.5654 ­ 0.0483t ­4.72* D*Cultivable waste In CUWA = 7.3567 + 0.0239t 2.43* D*Cultivable fallow In CUFA = 7.4162 + 0.0361t 3.68** A**Net area sown In NE AR S = 11.8259 +0.0060t 0.61* D*Area sown morethan onceTotal croppedareaIn AR S M O = 11.4932 ­0.0162t­1.61* D*In T CR AR = 12.3152 ­ 0.0015t ­0.15 D*Cgr= Compound growth rate, A= Acceleration;significance; **= 5% Level of significanceD=Deceleration; *=1% Level of28

Total area under forests in Thrissur district was estimated as 1389 haduring 1960­61 which gradually declined to 1214 ha during 1982­83 <strong>and</strong>then to 1036 ha during 2004­05 (Table. 3.2). Peechi­Vazhani WildlifeSanctuary is one of the major forest areas of Thrissur district <strong>and</strong>Karuvannur river basin <strong>and</strong> is also the main forest area in Manaliwatershed. The rate of forest denudation in Thrissur Forest Divisionshows that about 23 per cent forests were cleared for various purposesduring the 30 year period between 1930 <strong>and</strong> 1960 <strong>and</strong> during the period1960 to 1984 the rate almost doubled (50%) (Menon, 1986).Table 3.2. Area under forests in Thrissur district 1960­61 <strong>and</strong> 2004­05YEARAREA (ha)1960­61 1389.041961­62 1389.001962­63 1388.461963­64 1388.321964­65 1388.751965­66 1385.251966­67 1383.321967­68 1383.321968­69 1383.321969­70 1383.301970­71 1383.301971­72 1383.301972­73 1383.301973­74 1383.301974­75 1383.301975­76 1383.521976­77 1384.741977­78 1378.511978­79 1378.491979­80 1345.231980­81 1325.371981­82 1318.361982­83 1214.251983­84 1137.351984­85 1098.251985­86 1036.191986­87 1036.191987­88 1036.191988­89 1036.191989­90 1036.191990­91 1036.191991­92 1036.191992­93 1036.191993­94 1036.191994­95 1036.191995­96 1036.191996­97 1036.191997­98 1036.191998­99 1036.191999­2000 1036.192000­01 1036.192001­02 1036.192002­03 1036.192003­04 1036.192004­05 1036.19Source: State <strong>L<strong>and</strong></strong> <strong>Use</strong> Board, Thiruvanthapuram29

Between 1995 <strong>and</strong> 1973 different categories of forests in Thrissur districtshowed a declining trend. For instance, area under dense forests (canopycover >40%) showed a decline to 78 km 2 , open forests (canopy cover between20­40%) were declined to 177 km 2 <strong>and</strong> degraded forests (< 20% canopycover) were reduced to about 50 km 2 (Jha et al., 2000). In Pattikad <strong>and</strong>Peechi forest ranges where the Manali watershed is located, natural forestarea declined from 225 km 2 in 1930 to 179 km 2 in 1960 <strong>and</strong> further to109 km 2 in 1984 (Menon, 1986). The loss during the period 1930­1960was about 20 per cent while it was about 32 per cent during 1960­1984.This trend continued in the subsequent period also. Our analysis on l<strong>and</strong>use/cover change in Manali watershed during 1996­2004 indicated thatthe area under forests had been converted to agricultural l<strong>and</strong> on a largescale over the years (Figs. 3.1 & 3.2).Fig. 3.1 <strong>L<strong>and</strong></strong> cover map of Manali watershed based on 1996 IRS1Csatellite imageryFor instance, between 1996 <strong>and</strong> 2004, the area under agricultureprojected a 50 per cent increase (Table 3.3), which was effected mostlythrough conversion of forests.30

LAND COVER MAP OF MANALI WATESHEDBased on IRS 1 D (PAN+ LISS III ) imaginary of February 200476.1576.2076.2576.3010.35Vaniampara10.35ChuvannamannuPattikkaduMullakkaraOrappanparaOlakara10.30MannamangalamAlathur10.30TaloraKavallurEG/SEG HighScrubCherpuEG/SEG MediumWaterbodyPlantation10.2576.1576.20EG/SEG LowMD HighMD Medium76.25Agri.MixedAgri.Pure76.3010.25Fig.3.2<strong>L<strong>and</strong></strong> cover map of Manali watershed based on 2004 IRSP6(PAN+LISS3 merged) satellite imageryTable 3.3. Major changes in l<strong>and</strong> cover classes (1996­2004)Sl. No. Cover type Year Area (sq km) PercentageStudy area – 360 sq km1 Agricultural l<strong>and</strong> 1996 150 402 ,, ,, 2004 220 60Increase of agricultural l<strong>and</strong> ­­50%3 Forest l<strong>and</strong> 1996 210 604 ,, ,, 2004 140 405 Water holdings 2004 10 new un<strong>its</strong>6 <strong>Change</strong> of river course at Kavallur areaThere may be different conditions under which the l<strong>and</strong> use changesmight occur. These are given in Table 3.4. These conditions <strong>and</strong> responsesare different in different areas.31

Table 3.4 <strong>L<strong>and</strong></strong> use changes in a watershed: Conditions <strong>and</strong> responsesConditionsUpstream crops aremore lucrative(upstream unitprofit> downstreamunit profit)Downstream cropsare more lucrative(downstream unitprofit> upstreamunit profit)Downstream unitprofit=upstream unitprofitRelative profitabilityof crops in upstream<strong>and</strong> downstream;high input inupstream aloneRelative profitabilityof crops in upstream<strong>and</strong> downstream;high input indownstream alone<strong>L<strong>and</strong></strong> use change inupstreamNo change in l<strong>and</strong> use<strong>Change</strong> in l<strong>and</strong> useMore inputs leading tolow productivity <strong>and</strong> l<strong>and</strong>degradationAn early shift to otherlucrative crops<strong>L<strong>and</strong></strong> use changeinfluenced by externalindependent factors, viz.,innovative cropping(adapting new crops onexperimental basis, socioeconomicfactors inducedl<strong>and</strong> use change etc);social/cultural drivers<strong>Change</strong> in upstreamcropping pattern due toeconomic driversForced change in l<strong>and</strong>use owing to l<strong>and</strong>degradation, ecosystemimbalance <strong>and</strong> waterscarcity as a result of useby downstream users.<strong>L<strong>and</strong></strong> use change inDownstream<strong>Change</strong> in l<strong>and</strong> useMore inputs leading tolow productivity <strong>and</strong>l<strong>and</strong> degradation.An early shift to otherlucrative cropsNo change in l<strong>and</strong> use<strong>L<strong>and</strong></strong> use changeinfluenced by externalindependent factors,viz. innovative cropping(adopting new crops onexperimental basis,socio­economic factorsinduced l<strong>and</strong> usechange etc);social/cultural driversForced change in l<strong>and</strong>use owing tosedimentation,pollution <strong>and</strong> l<strong>and</strong>degradation by theupstream users.<strong>Change</strong> in downstreamcropping pattern due toeconomic drivers32

3. 2 Cropping patternCropping patterns denote area put under different crops. Agriculture isone of the main sources of income of the inhabitants of the area. Rice isthe staple food crop cultivated <strong>and</strong> crops like coconut, arecanut, tapioca,banana <strong>and</strong> pulses are also cultivated in the comm<strong>and</strong> areas of the PeechiIrrigation Project. Rice occupied about 24 per cent of the net cultivatedarea of the farmers <strong>and</strong> was followed by banana (22%), rubber (17% ),coconut (9% ), vegetables (10%) <strong>and</strong> pepper (7%). Cropping pattern variedin upl<strong>and</strong> <strong>and</strong> down stream areas of the watershed (Table 3.5).Table 3.5. Cropping pattern in up l<strong>and</strong> <strong>and</strong> down stream areas during 2005­06SlNo.CropTotalarea(ha)Percentageto totalareaUpl<strong>and</strong>(ha)33Percentageto total areaDownstreamPercentageto total area(ha)1 Paddy 30.71 23.78 1.16 2.43 29.55 36.262 Coconut 11.08 8.58 2.74 5.76 8.34 10.233 Arecanut 1.73 1.34 0.78 1.64 0.95 1.164 Pepper 8.96 6.94 5.65 11.86 3.31 4.065 Jack 0.61 0.47 0.25 0.53 0.36 0.446 Mango 0.92 0.71 0.37 0.77 0.55 0.677 Cashew 1.40 1.08 1.16 2.44 0.23 0.298 Tamarind 0.12 0.10 0.03 0.07 0.09 0.1110 Tapioca 5.75 4.46 4.44 9.32 1.32 1.6211 Nutmeg 1.29 1.00 0.15 0.31 1.14 1.4012 Vegetables 12.32 9.54 5.60 11.75 6.72 8.2513 Pulses 1.35 1.04 0.85 1.78 0.50 0.6114 Banana 28.20 21.84 8.46 17.77 19.74 24.2215 Ginger 0.82 0.64 0.33 0.68 0.49 0.6116 Turmeric 0.70 0.54 0.59 1.23 0.12 0.1417 Medicinal Plants 0.13 0.10 0.00 0.00 0.13 0.1618 Rubber 21.89 16.95 14.67 30.80 7.22 8.8619 Vanilla 0.13 0.10 0.02 0.05 0.11 0.1320 Others 1.02 0.79 0.37 0.79 0.64 0.7921 Fallow 0.00 0.00 0.00 0.00 0.00 0.0022 Forest area 0.00 0.00 0.00 0.00 0.00 0.00Total 129.14 100.00 47.63 100.00 81.51 100.00

In the upl<strong>and</strong> areas, a variety of crops like coconut, arecanut, rubber,pepper, banana, vegetables <strong>and</strong> tapioca were grown. Rubber was themajor crop cultivated in the upl<strong>and</strong>s, accounting for 31 per cent of the netcultivated area. This was followed by banana which accounted for 18 percent. Vegetables <strong>and</strong> pepper constituted 12 per cent each <strong>and</strong> tapiocaoccupied 10 per cent of the net cultivated area. In the down stream areasof the watershed, rice constituted the major crop occupying 36 per cent ofthe area cultivated by the selected farmers, followed by banana (24%),coconut (10% ) <strong>and</strong> rubber (9%). Cultivation of vegetables was undertakenin about 8 per cent of net cultivated area.Cropping pattern changes from 1975­76 to 2005­06A comparative analysis of area under different crops in the watershedduring 1975­76 <strong>and</strong> 2005­06, based on data collected from the selectedfarmers, revealed that there was a shift in area under the crops (Table3.6). The area under rice showed a definite decline, during the analysisperiod, accounting for only 27.68 per cent. A significant decrease in thearea was noticed in the case of cashew also. Among the crops that showedan increasing trend, tapioca <strong>and</strong> rubber were at the top, followed bybanana <strong>and</strong> coconut. The cultivation of rubber in the upl<strong>and</strong> areas hadbeen initiated during the mid 1950’s. Later large areas were brought underrubber with the intention of evading the proposed l<strong>and</strong> reforms in thestate, which favoured the plantations. Later on, a higher dem<strong>and</strong> <strong>and</strong>price boom resulted in the area expansion of rubber plantations. Forinstance, the price of a quintal of rubber in 1970 was Rs. 465 whichincreased to Rs. 1154 in 1980, to Rs. 2174 in 1990 <strong>and</strong> to Rs. 5660 in2005 (Government of Kerala, 2005).34

Table 3.6 Cropping pattern: A comparative data of 1975­76 <strong>and</strong> 2005­06Sl NOCropArea inhectares1975­76Percentageto totalareaArea inhectares2005­06Percentage tototal areaPercentagechange1 Paddy 39.21 30.36 30.71 23.78 ­27.682 Coconut 9.63 7.46 11.08 8.58 13.073 Areca nut 1.43 1.11 1.73 1.34 17.244 Pepper 7.38 5.71 8.96 6.94 17.655 Jack 0.59 0.46 0.61 0.47 2.916 Mango 0.89 0.69 0.92 0.71 2.757 Cashew 3.35 2.59 1.40 1.08 ­139.558 Tamarind 0.16 0.12 0.12 0.10 ­28.5510 Tapioca 3.26 2.52 5.75 4.46 43.3511 Nutmeg 1.12 0.87 1.29 1.00 13.0812 Vegetables 9.63 7.46 12.32 9.54 21.8513 Pulses 1.26 0.98 1.35 1.04 6.4714 Banana 19.38 15.01 28.20 21.84 31.2815 Ginger 0.76 0.59 0.82 0.64 7.3216 Turmeric 0.68 0.53 0.70 0.54 3.2617 Medicinal Plants 0 0.00 0.13 0.10 100.0018 Rubber 13.56 10.50 21.89 16.95 38.0619 Vanilla 0 0.00 0.13 0.10 100.0020 Others 4.35 3.37 1.02 0.79 ­327.4321 Fallow 9.25 7.1622 Forest area 3.25 2.52Total 129.14 100.00 129.14 100.003.3 <strong>L<strong>and</strong></strong> use <strong>and</strong> cropping pattern changes: Bio­physical <strong>and</strong> socioeconomicdriversIt was clearly evident that there have been drastic changes in the l<strong>and</strong> use<strong>and</strong> cropping pattern in the watershed under study <strong>and</strong> this posed a verypertinent question as to what are the drivers/causes of l<strong>and</strong> use <strong>and</strong>cropping pattern changes in the study area. For the purpose, an attempt35

has been made to analyze <strong>and</strong> examine the major causes for l<strong>and</strong> use <strong>and</strong>cropping pattern changes in the watershed.Generally, a number of drivers trigger l<strong>and</strong> use <strong>and</strong> cropping patternchanges <strong>and</strong> for analysis purpose, these may be grouped into direct <strong>and</strong>proximate causes (Briassoulis, 2000). Some of these causes arebiophysical in nature <strong>and</strong> others are socio­economic. The biophysicaldrivers include natural factors such as weather <strong>and</strong> climatic variations,soil types, plant succession, drainage pattern, etc. The socio­economicdrivers consist of demographic, social, economic, political <strong>and</strong>institutional factors. Since it is pointed out that the biophysical driversusually do not cause direct l<strong>and</strong> use <strong>and</strong> cropping pattern changes inmicro watersheds (Briassoulis, 2000), this study gives more emphasis onsocio­economic drivers of l<strong>and</strong> use <strong>and</strong> cropping pattern changes.Socio­economic driversAs observed in the survey, the major socio­economic drivers thatinfluenced l<strong>and</strong> use changes in the study area are given below.Deforestation, encroachment <strong>and</strong> population increaseThe deforestation in the study area could be traced back to a period asearly as 1940. Towards the end of the 2 nd world war, a huge deficit in foodproduction was experienced, which forced the authorities to launch growmore food scheme. This encouraged people to cut the forests <strong>and</strong> cultivatefood crops. In the erstwhile Cochin state where Thrissur was located,departmental cultivation of paddy was attempted during this period ineasily accessible forestl<strong>and</strong>. Since the cultivation was not profitable, theForest Department gave up this scheme <strong>and</strong> the cleared l<strong>and</strong>s were thenleased out to persons for food production (Karunakaran, 1986). Thisinitiated encroachment <strong>and</strong> migration of the people towards Peechi area.Except tribes, most of the people in the upl<strong>and</strong> areas were settlers, whomigrated from different parts of Kerala, particularly from erstwhile36

Travancore state during the 1950’s <strong>and</strong> 1960’s (Jayanarayanan, 2001).Availability of forest l<strong>and</strong> was one of the major attractions forimmigration. Immigration <strong>and</strong> encroachments continued rapidly till 1980<strong>and</strong> then dwindled due to policy changes in favour of forest protection.These were very high in <strong>its</strong> early years as the same were not considered aserious punishable offence during that period <strong>and</strong> also there were manyinstances in which encroachment were regularized by the government.Further, implementation of Forest Conservation Act of 1980 preventedclearance of forests for agriculture or other purposes. It was reported inour survey that there were only less than 500 people in Peechi villageduring early 1950’s. Over the years this has been changed <strong>and</strong> itcontinues to show an increasing trend. According to the Census 2001, thetotal population of Peechi village was 22409, with 11066 males <strong>and</strong> 11343females. It was estimated that there were about 60 tribal <strong>and</strong> 70 settlerfamilies living within the sanctuary <strong>and</strong> they possessed an area of 170 haof l<strong>and</strong> (Narayanankutty <strong>and</strong> Nair, 1990). Almost all the people who live in<strong>and</strong> around the Manali watershed depended on forests for their livelihood;by collecting forest goods <strong>and</strong> using water either from Dam or river.Agricultural expansionThere were no reliable time series data to examine the expansion ofagriculture in the watershed. However, it may be assumed that croppingin the upl<strong>and</strong> areas of the watershed was undertaken by clearing forestl<strong>and</strong> <strong>and</strong> therefore agricultural practices began with encroachment <strong>and</strong>migration to this area. At present about 80 per cent of the watershed areais under agricultural crops.Construction of reservoirThe construction of Dam has significantly affected the l<strong>and</strong> use in thewatershed. The availability of water was one of the reasons for conversionof forest l<strong>and</strong> to agricultural l<strong>and</strong>s. The construction of two canals from37

the reservoir enabled the farmers to get water for irrigation easily <strong>and</strong>cheaply <strong>and</strong> they allocated the l<strong>and</strong> under different crops, in accordancewith the availability of water. Tapioca was cultivated initially in thedeforested l<strong>and</strong>s <strong>and</strong> later they slowly shifted to more valuable crops suchas vegetables <strong>and</strong> paddy.Cropping pattern changes: ReasonsThe reasons for conversion of paddy l<strong>and</strong> to other crops are more complexin the study area <strong>and</strong> assume prime importance. Indeed, changes inaverage farm prices (at current price) between 1970 to 2004 indicate thatamong the major crops grown in Kerala, rice registered the lowest priceincrease of 699 percentages (Table 3.7). This may be one of the majorfactors which influenced the shift from rice to other crops. In addition,labor­management issues <strong>and</strong> the conversion of l<strong>and</strong> to meet populationneeds, such as housing <strong>and</strong> infrastructure, were some of the factors thatinduced conversion of rice l<strong>and</strong>.Table: 3.7. Percentage increase of prices of selected commodities during1970­2004Commodities UnitIncrease1970 1996 2004(with respect(Rs.) (Rs.) (Rs.)to 1970Paddy 100 kg 90 607 721 7 foldCoconut 100 nos. 56 480 611 10 foldTapioca 100 kg 20 300 392 18 foldBanana 100 nos. 16 161 1167 69 foldPepper 100 kg 616 8780 6975 10 foldGinger 100 kg 271 4214 10558 38 foldCashew 100 kg 139 2730 3123 21 foldRubber 100 kg 429 4900 5181 11 foldSource: Government of Kerala, 200538

Another important change in the cropping pattern was the increased areaunder banana, at the expense of rice. The benefit–cost ratios for rice <strong>and</strong>banana at Peechi were worked out to be 1.34 <strong>and</strong> 1.71 respectively(Suresh, 2000). The entry of Kerala Horticultural Development Programme(KHDP), currently known as Vegetable <strong>and</strong> Fruit Promotion Council ofKerala (VFPCK) into commercial banana production since 1993 has alsopromoted area under the banana. They helped farmers <strong>and</strong> even l<strong>and</strong>lesslabour to procure l<strong>and</strong> on lease <strong>and</strong> advanced/facilitated loan with thehelp of commercial banks. For instance, area under banana in Thrissurdistrict during 1975­76 was 1384 ha which increased to 1549 ha during1980­81, 1842 ha in 1990­91, 2128 ha in 1995­96 <strong>and</strong> 2475 ha in 1998­99 (Government of Kerala, 2000). Between 1970 <strong>and</strong> 2005, there was aphenomenal increase in the price of banana (Table 3.6).Another reason for reduction of paddy l<strong>and</strong> was conversion of the same toclay mining. Karuvannur river basin, particularly that of Manali is one ofthe important centres of clay mining. The history of clay mining in thestudy area could be traced back to over 100 years <strong>and</strong> this was at <strong>its</strong>peak during the mid 1970’s, when there was a boom in the constructionactivities in the state (Gopinathan <strong>and</strong> Sundaresan 1990). A number oftile factories <strong>and</strong> brick kilns were also established in the area. Our surveyshowed that many padasekharams (fields) have been completely degradeddue to severe clay mining <strong>and</strong> many of these areas have been flooded,which prevented flow of water to the river, resulting in reduction ofavailability of water in the river.The price of cashew has increased over a period of time but <strong>its</strong> area hasdeclined. Area under coconut showed an increasing trend though <strong>its</strong> priceshowed only minimum increase (Table 3.6). In the case of cashew nut,intercropping was not practiced, while in the coconut gardens, othercrops such as pepper, plantain, arecanut, tapioca, <strong>and</strong> tubers were alsowidely cultivated, which gave higher cash income to the farmers.39

Thus, the overall effect of reduction of wet l<strong>and</strong>s was the reduction ofarea under rice. Wet l<strong>and</strong>s are flood plain areas where water is held for along time. This helps to maintain water table in the nearby areas. Thereduction of wet l<strong>and</strong>s also affects ground water availability of the area.Many of the selected farmers in the low l<strong>and</strong> areas reported that there wasa drastic reduction of ground water table in recent years in their areas.Another important aspect behind the changes in the cropping pattern ispeople’s attitude towards agriculture. For the older generation agriculturewas a way of life, while, for the present generation, it is a commercialactivity. The latter therefore, utilizes it to earn as much money as possibleat a minimum cost <strong>and</strong> in the shortest time possible. Coconut respondsfavourably to cultural operations <strong>and</strong> once it starts yielding it does notrequire close attention. The inter­cropping system provides farmers with arange of outputs; it represents a logical approach to coping with variableenvironments. The total value of the yield from mixed crops is oftengreater, particularly if root <strong>and</strong> shoot formations of coconut allow thesecrops to use light, water, <strong>and</strong> nutrients efficiently. Inter­cropping not onlydiminishes the incidence of pests <strong>and</strong> weeds, but reduces water loss <strong>and</strong>soil erosion by providing greater ground cover as well. Still incomereceived from a unit of rubber cultivation was much higher than totalincome from a unit of garden l<strong>and</strong>s in the study area. Further, adverseterms of trade, that is price paid by the farmers is higher than pricereceived by the farmers, also forced the farmers to undertake the aboveactivities in the farming sector.40

Chapter 4HYDROLOGICAL STUDIESEffect of l<strong>and</strong>use changes on hydrology in the study area is attempted inthis chapter. The study analyses the effects of l<strong>and</strong>use changes at riverbasin as well as selected watershed levels. The results <strong>and</strong> discussionsare presented separately in two sub­sections in this chapter.Section 1 Results4.1 Historical data on annual rainfall distributionFor the sake of hydrological studies, Karuvannur basin is divided intothree zones ­ Zone 1 comprises of the area in the upper portions ofKaruvannur river basin that form the catchment area of Peechi, Chimony<strong>and</strong> Muply reservoirs, of which Peechi <strong>and</strong> Chimony are existingreservoirs, <strong>and</strong> Muply is a proposed one. Zone 2 consists of a portion ofthe Karuvannur river basin upstream of the lowest discharge station atKaruvannur Bridge excluding Zone 1. Zone 3 comprises the portion of theKaruvannur river basin downstream of the lowest discharge station atKaruvannur bridge. The annual distribution of rainfall since 1966 (since1973 for Zone 1) is given in Fig.4.1. The details of each zone are given inTables 4.1 to 4.3.Almost the same trend was shown in the three regions. The averageannual rainfall in highl<strong>and</strong> (Zone 1) is estimated as 2851 mm, for midl<strong>and</strong>(Zone 2) 3011mm, <strong>and</strong> the low l<strong>and</strong> (Zone 3) it is estimated as 2858 mm.About 60 per cent of the rainfall was received during Southwest Monsoonperiod <strong>and</strong> 30 per cent during Northeast monsoon <strong>and</strong> the remaining 10per cent as summer rainfall in all the three zones.41

Annual Distribution of Rainfall at Kannara (Zone 1 ­ Highl<strong>and</strong>)5000400030002000100001971197319751977197919811983Rainfall (mm)1985198719891991199319951997199920012003YearAnnual distribution of Rainfall at Var<strong>and</strong>arappilly (Zone 2 ­ Midl<strong>and</strong>)50004000300020001000019661968197019721974197619781980198219841986198819901992199419961998Rainfall (mm)2000YearAnnual distribution of Rainfall at Enamakkal (Zone 3 ­ Lowl<strong>and</strong>)500040003000200010000196619681970197219741976197819801982198419861988199019921994199619982000Rainfall (mm)YearFig.4.1 Annual rainfall distribution from the three zones in the Karuvannur river basin42

Table 4.1Mean monsoon, non­monsoon <strong>and</strong> annual rainfall in Zone 1 ofKaruvannur River BasinDescription of Zone 1Area of Zone 1: Upper portions of Karuvannur river basin that form thecatchment area of Peechi, Chimony <strong>and</strong> Muply reservoirsPeechi <strong>and</strong> Chimony are existing reservoirs, <strong>and</strong> Muply is aproposed one: 220 sq. kmSl.No.RainfallStationsFalling withinZone 1Period for which RainfallData is consideredStartingYearEndingYearNumberof YearsMean Rainfall in millimetres(mm)Monsoon Non­monsoon(Jun ­ Nov) (Dec ­ May)Annual(Jun­May)1 Irumpupalam 1980­81 2000­01 22 2,499 262 2,7862 Kallichitra 1968­69 1989­90 22 2,977 350 3,5163 Pottimada 1979­80 2000­01 23 2,149 247 2,413For the Zone as a whole in mm* Mean 2,542 286 2,905* Maximum 2,977 350 3,516* Minimum 2,149 247 2,413Table 4.2. Mean monsoon, non­monsoon <strong>and</strong> annual rainfall in Zone 2 ofKaruvannur River BasinDescription of Zone 2 : The portion of the Karuvannur river basin upstream of the lowestdischarge station at Karuvannur Bridge excluding Zone 1Area of Zone 2 : 505 sq.kmSl.No.RainfallStationsFalling withinZone 2Period for which RainfallData is ConsideredStartingYearEndingYearNumberof Years43Mean Rainfallin millimetres (mm)Nonmonsoon(Dec ­ May)Monsoon(Jun ­ Nov)Annual(Jun­May)1 Ollukkara 1969­70 2002­03 34 2,339 280 2,6512 Peechi 1966­67 2001­02 36 2,408 250 2,6763 Echipara 1979­80 2001­02 23 2,794 315 3,1554 KannaraC.P.C.R.I1971­72 2002­03 32 2,472 294 2,9815 PudukkadEstate1971­72 2000­01 30 2,660 398 3,0606 Muply Estate 1969­70 1999­2000 31 2,736 366 3,1097 Var<strong>and</strong>rappilli 1966­67 2001­02 36 2,661 360 3,0558 Karikadavu 1967­68 2001­02 35 2,768 414 3,199For the Zone as a whole in mm* Mean 2,651 335 2,986* Maximum 2,794 414 3,199* Minimum 2,339 250 2,651

Table 4.3Mean Monsoon, Non­monsoon <strong>and</strong> Annual Rainfall in Zone 3 ofKaruvannur River BasinDescription of Zone 3Area of Zone 3: The portion of the Karuvannur river basin downstreamof the lowest discharge station at Karuvannur Bridge: 325 sq.kmSl.RainfallStationsPeriod for which RainfallData is ConsideredMean Rainfall in Millimetres(mm)No.Falling withinZone 3StartingYearEndingYearNumberof YearsMonsoon(Jun ­ Nov)Nonmonsoon(Dec ­ May)Annual(Jun ­May)1 Enamakkal 1966­67 2000­01 35 2,392 343 2,7502 Trichur I.C.C 1982­83 1997­98 16 2,449 269 2,7183 Trichur R.S 1971­72 1993­94 23 2,416 268 2,6414 Trichur T.O 1967­68 1994­95 28 2,363 249 2,6125 Irinjalakuda 1978­79 2002­03 37 2,377 300 2,699For the Zone as a whole in mm* Mean 2,398 286 2,684* Maximum 2,449 343 2,750* Minimum 2,363 249 2,612River dischargeData regarding river discharge at the various stations of the Karuvannurriver basin were collected from the Hydrology Department of the Governmentof Kerala. Graphs showing the annual river discharge are given (Fig.4.2).RainfallDetails of monthly total rainfall for 2005 <strong>and</strong> 2006 received in thewatersheds at Olakara <strong>and</strong> Kavallur are presented in the Table 4.4.44

Yearly Discharge at Kurumali bridgeDischarge (m 3 /sec)250020001500100050001963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993YearYearly Discharge at Manali bridgeDischarge (m 3 /sec)250020001500100050001963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993YearYearly Discharge at Karuvannur bridge2500Discharge (m 3 /sec)20001500100050001964 1967 1970 1973 1976 1979 1982 1985 1988 1991YearFig.4.2. Annual river discharge in the Karuvannur river basin45

Table 4.4 Rainfall for Olakara <strong>and</strong> Kavellur recorded during 2005 to 2006Olakara Rain fall (mm)Months 2005 2006 MeanJan 0 0 0Feb 70 1 35.5Mar 12.8 92.4 52.6Apr 165 104 134.5May 68 446.8 257.4Jun 614.7 607.4 611.05Jul 552 423 487.5Aug 98 373.4 235.7Sep 339.6 345.4 342.5Oct 62.8 313.6 188.2Nov 49.4 74 61.7Dec 26.2 0.0 26.2Total 2058.5 2781 2432.85Kavallur Rain fall (mm)Months 2005 2006 MeanJan 0 0.4 0.2Feb 90.6 0.0 45.3Mar 17.4 89.6 53.5Apr 171.4 83.0 127.2May 85 511.8 298.4Jun 677.6 538.7 608.2Jul 665.8 507.8 586.8Aug 102.4 304.0 203.2Sep 349.2 296.6 322.9Oct 112.8 157.9 135.3Nov 38.08 49.1 43.6Dec 12.67 0.0 12.7Total 2323.0 2538.8 2437.2The Table 4.4 indicates that the total mean annual rainfall during the period(2005­06) was 2432 mm <strong>and</strong> 2437 mm for Olakara <strong>and</strong> Kavallurrespectively. For both sites, maximum rainfall was received during the periodJune <strong>and</strong> July followed by September. For both watersheds, approximately60 per cent of the total rainfall was received during June <strong>and</strong> July.The percentage distribution of rainfall during the months of June, July<strong>and</strong> September for Kavallur was 24.95 per cent, 24.07 per cent <strong>and</strong> 13.24per cent out of the total rain respectively while for Olakara it was recordedas 25.11 per cent, 20.03 per cent, <strong>and</strong> 14.07 per cent out of the total rainrespectively. The monthly rainfall was less than 50 mm during December,January <strong>and</strong> February for both the areas. From the above rainfall dataanalysis, it was clear that both sites experienced a seasonal distributionof rainfall. Mean monthly distribution of rainfall for both sites is given inthe graph (Fig.4.3). The seasonal pattern <strong>and</strong> the quantity of rainfallreceived at both the locations were similar.46

Olakara RainfallKavallur Rainfall7007006006005005004004003003002001000Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec2001000J an Feb Mar Apr May J un J ul Aug Sep Oc t Nov DecFig.4. 3 Monthly distribution of rainfall at the two selected watersheds of Olakara <strong>and</strong>KavallurSeasonal distribution of rainfallDetails of seasonal rainfall for Kavallur <strong>and</strong> Olakara sites are given inTable 4.5. For Kavallur, it was found that out of the total rainfall 78 percent accounts for the monsoon period (June­November), 10 per cent postmonsoon (December – April) <strong>and</strong> 12 per cent during pre monsoon (May). Asimilar seasonal distribution was found for Olakara (Table 4.5).Table 4.5 Seasonal Distribution of rainfall at Kavallur <strong>and</strong> OlakaraSeason Kavallur OlakaraPremonsoon (May) 298.4 (12 % ) 257.4 (11 %)Monsoon (June­ November) 1900 (78 %) 1676.75 (79 %)Post monsoon (December­April) 238.9 (10 % ) 276.1 (10 %)Stream FlowRun off is the portion of precipitation that makes <strong>its</strong> way to streamchannels as surface or subsurface flow. The peak run off rate <strong>and</strong> run offvolume are of great importance in the planning <strong>and</strong> design of soilconservation works. For the measurement of run off, gauging stations were47

installed at both the micro watersheds at Kavallur <strong>and</strong> Olakara. Stream ofKavallur is flowing through mixed plantation area while Olakara it isthrough a moist deciduous forestl<strong>and</strong> (plate 1). The drainage area of thestream at Kavallur is calculated as 2.6 km 2 <strong>and</strong> that of Olakara is 3.2km 2 .Plate 1: Run­off measurement at OlakaraThe observed values of the stream flow for Kavallur <strong>and</strong> Olakarawatershed for the period 2005­2006 is given on the Tables 4.6 <strong>and</strong> 4.7.Table 4.6 Stream flow recorded atOlakara during 2005 to 2006Stream flow (m 3 /sec)Months 2005 2006 MeanJanuary 0 0 0February 0 0 0March 0 0 0April 0 0 0May 0.019 0.010 0.014June 0.239 0.443 0.341July 0.302 0.797 0.549August 0.272 0.205 0.238September 0.111 0.244 0.177October 0.048 0.258 0.153November 0.021 0.053 0.037December 0.003 0.007 0.005Table 4.7 Stream flow recorded atKavallur during 2005 to 2006Stream flow (m 3 /sec)Months 2005 2006 MeanJanuary 0 0 0February 0 0 0March 0 0 0April 0 0 0May 0.002 0.023 0.012June 0.296 0.640 0.468July 0.327 0.426 0.376August 0.205 0.471 0.338September 0.176 0.370 0.273October 0.039 0.068 0.053November 0.001 0.002 0.002December 0 0 048

In Olakara watershed, maximum flow was recorded during the month of Julyboth in 2005 <strong>and</strong> 2006 followed by June, while in Kavallur watershedmaximum flow was recorded during June followed by July in 2006. Theflow at Kavallur area decreased drastically after September <strong>and</strong> thereafternegligible flow was recorded. But, in Olakara watershed, the duration of flow wasmore than that of Kavallur lasting up to December. There was no flow duringthe first four months of the year. The duration of flow at Olakara, whichhas a forested stream is higher than other one. This difference in the dischargepattern at the two sites may be due to the difference in the l<strong>and</strong>use patternof the sites under study. This implies the lag time available for rainwaterfor recharge in the case of forested area (Olakara), but in Kavallur, predominantlyplantation <strong>and</strong> agricultural area, the peak flow coincides with peak rainfall<strong>and</strong> hence surface runoff is more. It may be due to the fact that water retentioncapacity of the forested watershed is higher than that of the non­forestedwatershed. It is because the watershed under forest on which a thick layerof mulch of leaves <strong>and</strong> grasses have accumulated, the surface runoff becomesless <strong>and</strong> more amount of rainfall is absorbed by the soil due to increase ininfiltration rate <strong>and</strong> formation of resistance in the flow path of the water overground surface, resulting in a more sustained base flow. Details of meanmonthly stream flow for both the watersheds are given in the graph (Fig.4.4).OlakaraStream flow (m 3 /sec)0.60.50.40.30.20.10KavallurJanFebMarAprilMayJuneJulyAugustSeptemberOctoberNovemberDecemberMonthsFig.4.4. Monthly stream flow for both the watersheds during the year 2005 to 200649

From the graph it may be noted that maximum flow for Olakara was inthe month of July while for Kavallur it was in June. Flow at Kavallurbecomes negligible after October, but in Olakara flow lasts up toDecember. For both watersheds peak flow occurs during the months ofJune <strong>and</strong> July. Tables 4.8 <strong>and</strong> 4.9 present the total monthly stream flowas the percentage of total monthly rainfall. For the same purpose thestream flow is converted in terms of depth of flow <strong>and</strong> given in the aboveTables.Table 4.8 Stream flow at Olakara as a percentage of the rainfallMonthRainfall Stream flow Stream flow as(mm)(mm) percentage of Rain fallJanuary 0 0 0February 35.5 0 0March 52.6 0 0April 134.5 0 0May 257.4 11.664 8.6June 611.05 276.372 45.2July 487.5 444.852 91.2August 235.7 193.104 81.9September 342.5 143.532 41.9October 188.2 123.768 65.7November 61.7 43.092 69.8December 26.2 5.508 21.02It may be noted that the initial percentage of runoff with rainfall for bothsites was almost similar. Olakara recorded a runoff percentage of 8.6 percent while Kavallur it was 9.6 per cent. As the rain increased with themonsoon the percentage of run off also increased for both sites. The rateof increase in percentage of runoff with rainfall for Olakara was recordedin the range of 8.6­91.2 per cent while in Kavallur site the rate was 9.6­165.8 per cent, an increase of 1.8 times than that of Olakara. Themonthly rain recorded during June was 611.05 mm for Olakara in June50

Table 4.9 Stream flow at Kavallur as a percentage of the rainfallMonth Rainfall Stream flow (mm)Stream flow aspercentage of Rain fallJanuary 0.2 0 0February 45.3 0 0March 53.5 0 0April 127.22 0 0May 298.4 12.312 9.6June 608.16 466.56 76.7July 586.775 414.72 70.6August 203.214 336.96 165.8September 322.88 272.16 84.29October 135.33 53.136 39.26November 43.585 36.936 84.74December 12.67 0 0<strong>and</strong> the run off observed in the same month was 276.37 mm, whichaccounted for 45.2 per cent of rainfall. But in Kavallur watershed, thehighest rainfall recorded in the same month was 608.16 mm <strong>and</strong> the runoff recorded was 466.56 mm, constituting 76.7 per cent of the rainfall.This shows that percentage of surface run off was much more in Kavallurwatershed. For both watersheds, the rainfall received during August waslower than that received in June <strong>and</strong> July; the percentage run off washigher than these months which were 91.2 per cent <strong>and</strong> 165.8 per centfor Olakara <strong>and</strong> Kavallur respectively. During the initial months of themonsoon period, the rate of stream flow was found less in both sites. Thismay be because of rainwater infiltration into the soil for filling the porespaces during the period immediately following commencement of therainy season. As the soil gets saturated, the infiltration rate decreases <strong>and</strong>the rate of run off increases. As rainfall continues, soil becomesincreasingly saturated <strong>and</strong> infiltration is stabilized, thereby more water is51

available for both surface <strong>and</strong> base flow runoff. From the data it can beseen that the percentage run off with respect to rainfall was less inforested watershed than other non­forested watershed although there waseven distribution of rainfall in both watersheds. So it can be concludedthat forested area have higher water accumulation capacity than the nonforestedwatershed resulting in more sustained base flow. Therelationship between rainfall <strong>and</strong> stream flow at Olakara <strong>and</strong> Kavallur isshown in Fig. 4.5.Streamflow(mm )/Rainfall(mm)7006005004003002001000J anFebMarOlakaraAprilMayJuneJulyMonthAugustSeptemberRainStream flowOctoberNovemberDecemberStreamflow/Rainfall7006005004003002001000JanFebMarAprilKavallurMayJ uneJulyAugustMonthRainfallStream flowSeptemberOctoberNovemberDecemberFig.4.5. Relationship between rainfall <strong>and</strong> stream flow at Olakara <strong>and</strong> KavallurFrom the graph it can be noted that as the amount of rainfall increases,stream flow also increases. But the amount of flow generated is higher inKavallur area than that at Olakara.4.2 Average seasonal stream discharge at the study areaData on mean seasonal flows for the three streams calculated for bothOlakara <strong>and</strong> Kavallur watersheds are given in Table 4.10. Maximum flowwas recorded in both watersheds during monsoon period. For Olakara,total flow during monsoon season was 1224 mm, accounting for 98 percent of total stream flow. The flow in Kavallur during monsoon season was1580 mm, constituting 99 per cent of total run off. Flow during postmonsoon <strong>and</strong> pre monsoon seasons through Kavallur was less than thatof Olakara site by one per cent because the duration of the flow atOlakara site was more than that of Kavallur site.52

Table 4.10Seasonal distribution of stream flow at Olakara <strong>and</strong> Kavallurworked out as a mean from the data for 2005 <strong>and</strong> 2006Season Olakara (mm) Kavallur (mm)Pre monsoon 11.664 (9.39% ) 90.072 (5.39%)Monsoon 1224 (98%) 1580 (99%)Post monsoon 172.368 (13.87%) 90.072 (5.3% )Stream flow as a percentage of the rainfall worked out for the years 2005<strong>and</strong> 2006 is given in Table 4.11. The total run off observed during theperiod was 1241.89 mm for Olakara site against a total rain fall of2432.85 mm which is 51.04 per cent of the total rainfall.Table 4.11Stream flow as a percentage of the rainfall worked out for theyears 2005 <strong>and</strong> 2006SiteTotal Rainfall(mm)Total Streamflow (mm)Percentage of Runoffwith RainfallOlakara 2432.85 1241.89 51.04Kavallur 2437.23 1592.78 65.35At Kavallur site the total runoff was 1592.78 mm for a rainfall of 2437.23mm, constituting 65.35 per cent of the total rainfall. Percentage of wateryielded as surface <strong>and</strong> base flow total runoff is less in forested areacompared to the non­forested watershed. The correlation between therainfall <strong>and</strong> stream discharge has been established. The regressionequations depicting the relationship are given below.Olakara Y=0.615X­21.32 R 2 =0.71Kavallur Y=0.752X­20.026 R 2 =0.76where Y= stream flow <strong>and</strong> X= rainfallBoth sites showed a positive relationship between stream flow <strong>and</strong>rainfall.53

4.3 Ground Water TableThe ground water table observations for the watersheds of Olakara <strong>and</strong>Kavallur are given in Tables 4.12 to 4.16. The monthly observations showvery little variations for the same well during any given month. For bothwatersheds, highest water table was observed between the months of June <strong>and</strong>July during 2005 <strong>and</strong> 2006. For Kavallur, the lowest water table was observedduring the month of April for 2005 <strong>and</strong> 2006 while the lowest water table forOlakara was in the month of March during 2005 <strong>and</strong> 2006 ( Fig. 4.6 <strong>and</strong> 4.7)Table 4.12 Monthly water table depth in different wells at Olakara during 2005<strong>and</strong> 2006 (m)Months OW­1 OW­2 OW­3 OW­4 OW­5 OW­6 OW­7 OW­8Mar 05 5.06 2.36 4.25 7.45 4.09 7.51 4.96 8.06Apr 05 4.97 2.28 4.27 7.60 4.63 7.58 4.96 8.08May 05 5.31 2.56 4.86 7.74 4.34 7.81 5.07 8.41Jun 05 3.78 2.05 3.39 7.55 3.43 6.38 4.08 7.68Jul 05 1.90 0.55 2.32 6.20 2.62 4.21 1.17 5.68Aug 05 2.30 0.62 2.53 6.12 2.51 4.33 1.60 5.25Sept 05 2.71 0.67 2.47 6.03 2.72 5.01 3.62 6.02Oct 05 3.58 1.03 2.52 6.21 2.72 5.80 4.30 6.70Nov 05 3.85 1.38 2.93 6.66 2.81 6.19 4.57 6.96Dec 05 3.92 1.85 3.27 6.88 2.83 6.51 4.64 7.22Jan 06 4.04 2.05 3.53 6.88 2.89 6.91 4.72 7.38Feb 06 4.42 2.31 3.95 6.99 3.47 7.44 4.87 7.74Mar 06 4.79 2.49 4.40 7.35 4.49 7.58 4.98 8.18Apr 06 4.64 2.51 4.35 7.43 4.79 7.64 4.96 8.12May 06 5.15 2.60 4.82 7.61 4.54 7.89 5.04 8.34June 06 4.31 1.70 4.01 6.78 3.69 6.86 4.05 7.61Jul­06 2.89 0.85 2.64 4.75 2.41 5.49 2.75 6.28Aug­06 2.65 0.65 2.32 4.57 2.24 5.32 2.34 6.05Sep­06 1.82 0.62 2.14 3.12 1.80 3.87 2.01 5.58Oct­06 1.85 1.05 1.76 2.74 1.83 3.18 2.00 3.58Nov­06 2.90 1.57 2.18 5.05 2.83 4.15 2.98 4.02* Values recorded in meters as the depth from the ground level.54

Table 4.13 Monthly water table depth at Olakara during 2005 <strong>and</strong> 2006 (m)Months OW­1 OW­2 OW­3 OW­4 OW­5 OW­6 OW­7 OW­8 AverageMar 05Apr 05 0.10 0.08 ­0.02 ­0.15 ­0.54 ­0.07 0.00 ­0.02 ­0.08May 05 ­0.34 ­0.28 ­0.59 ­0.14 0.29 ­0.23 ­0.12 ­0.33 ­0.22Jun 05 1.53 0.51 1.47 0.20 0.92 1.44 0.99 0.73 0.97Jul 05 1.88 1.51 1.07 1.35 0.81 2.17 2.91 2.00 1.71Aug 05 ­0.41 ­0.07 ­0.21 0.08 0.12 ­0.12 ­0.43 0.44 ­0.07Sept 05 ­0.41 ­0.06 0.05 0.09 ­0.22 ­0.69 ­2.03 ­0.77 ­0.50Oct 05 ­0.87 ­0.35 ­0.04 ­0.18 0.00 ­0.79 ­0.68 ­0.68 ­0.45Nov 05 ­0.28 ­0.36 ­0.41 ­0.45 ­0.09 ­0.39 ­0.27 ­0.26 ­0.31Dec 05 ­0.07 ­0.47 ­0.34 ­0.22 ­0.02 ­0.32 ­0.07 ­0.26 ­0.22Jan 06 ­0.12 ­0.21 ­0.27 0.00 ­0.06 ­0.40 ­0.08 ­0.17 ­0.16Feb 06 ­0.38 ­0.26 ­0.42 ­0.11 ­0.59 ­0.53 ­0.16 ­0.36 ­0.35Mar 06 ­0.37 ­0.18 ­0.46 ­0.36 ­1.02 ­0.15 ­0.11 ­0.44 ­0.38Apr 06 0.15 ­0.02 0.05 ­0.08 ­0.30 ­0.06 0.02 0.06 ­0.02May 06 ­0.52 ­0.09 ­0.47 ­0.18 0.25 ­0.25 ­0.08 ­0.22 ­0.19June 06 0.84 0.90 0.81 0.83 0.85 1.03 0.99 0.73 0.87Jul­06 1.42 0.85 1.37 2.03 1.28 1.37 1.29 1.33 1.37Aug­06 0.24 0.20 0.32 0.18 0.17 0.17 0.41 0.23 0.24Sep­06 0.83 0.03 0.18 1.45 0.44 1.45 0.33 0.47 0.65Oct­06 ­0.03 ­0.43 0.38 0.38 ­0.03 0.69 0.01 2.00 0.37Nov­06 ­1.05 ­0.52 ­0.42 ­2.31 ­1.00 ­0.97 ­0.98 ­0.44 ­0.96Table 4.14 Monthly water table depth during 2005 to 2006 at Kavallur (m)Months KW­1 KW­2 KW­3 KW­4 KW­5 KW­6 KW­7 KW­8 KW­9 KW­10 KW­Mar 05 6.29 3.93 7.25 4.84 5.95 7.10 4.34 4.52 4.90 7.14 7.54Apr 05 6.78 4.17 7.30 4.88 5.97 7.86 4.37 4.79 4.25 7.25 7.39May 05 7.35 4.13 7.14 4.98 6.05 7.85 4.33 4.81 4.69 7.67 7.85Jun 05 6.13 2.89 5.86 3.32 4.45 6.09 2.50 3.66 2.38 5.32 5.72Jul 05 2.98 2.67 4.11 2.78 3.96 3.97 1.74 3.11 2.14 3.72 4.031155

Table 4.14 contd…Months KW­1 KW­2 KW­3 KW­4 KW­5 KW­6 KW­7 KW­8 KW­9 KW­10 KW­Aug 05 3.44 2.87 4.70 3.55 4.73 4.84 1.98 3.26 2.71 3.76 3.84Sept 05 2.94 3.07 3.93 3.13 4.21 4.03 2.10 3.40 1.50 3.95 4.19Oct 05 4.16 3.04 5.28 4.15 5.27 5.88 2.61 3.73 2.98 5.42 5.46Nov 05 4.44 2.96 5.47 4.20 5.33 6.26 2.72 3.82 2.88 5.56 5.77Dec 05 4.76 2.98 5.75 4.45 5.55 6.50 2.87 3.94 3.07 5.88 6.31Jan 06 5.02 3.12 5.98 4.59 5.68 6.69 3.39 4.01 3.17 6.08 6.42Feb 06 5.42 3.25 6.21 4.99 6.06 6.92 4.14 4.39 3.63 6.47 6.71Mar 06 5.64 3.69 6.45 4.67 6.62 7.69 4.72 4.46 4.07 6.83 7.05Apr 06 5.77 3.80 6.57 4.76 6.77 7.79 4.77 4.56 4.15 6.94 7.17May 06 5.73 3.82 6.56 4.71 6.78 7.82 4.79 4.55 4.15 7.03 7.34June 06 4.89 2.82 5.57 3.62 5.63 6.57 3.57 3.75 3.23 6.24 6.46Jul­06 3.30 2.72 4.59 2.93 4.08 6.29 3.27 3.29 2.96 5.81 6.06Aug­06 2.77 2.31 4.02 2.42 3.63 5.72 2.80 2.84 2.41 5.30 5.57Sep­06 2.55 3.12 3.98 3.21 4.22 4.12 2.10 3.45 1.25 4.12 4.08Oct­06 2.12 2.66 3.68 2.95 3.98 4.10 2.08 3.14 1.02 4.01 3.98Nov­06 2.75 3.01 4.10 3.21 4.25 4.87 2.54 3.55 1.80 4.58 4.25Values recorded in meters as the depth from the ground level.Table 4.15 Water table fluctuations in the different wells during 2005 <strong>and</strong> 2006 atKavallur (m)Months KW­1 KW­2 KW­3 KW­4 KW­5 KW­6 KW­7 KW­8 KW­9KW­10 KW­ Average11Mar 05Apr 05 ­0.49 ­0.24 ­0.05 ­0.04 ­0.02 ­0.76 ­0.04 ­0.27 0.65 ­0.11 0.15 ­0.11May 05 ­0.56 0.04 0.16 ­0.10 ­0.08 0.01 0.04 ­0.02 ­0.44 ­0.42 ­0.46 ­0.17Jun 05 1.22 1.24 1.28 1.67 1.61 1.77 1.83 1.15 2.31 2.36 2.13 1.69Jul 05 3.15 0.23 1.76 0.54 0.49 2.12 0.77 0.56 0.24 1.60 1.69 1.19Aug 05 ­0.46 ­0.21 ­0.60 ­0.78 ­0.77 ­0.87 ­0.24 ­0.16 ­0.57 ­0.04 0.20 ­0.41Sept 05 0.50 ­0.20 0.77 0.42 0.52 0.81 ­0.12 ­0.14 1.21 ­0.20 ­0.36 0.29Oct 05 ­1.22 0.03 ­1.35 ­1.02 ­1.06 ­1.85 ­0.52 ­0.33 ­1.48 ­1.47 ­1.27 ­1.055611

Table 4.15 contd…Months KW­1 KW­2 KW­3 KW­4 KW­5 KW­6 KW­7 KW­8 KW­9 KW­10 KW­ Average11Nov 05 ­0.28 0.08 ­0.19 ­0.06 ­0.06 ­0.38 ­0.11 ­0.09 0.11 ­0.14 ­0.31 ­0.13Dec 05 ­0.33 ­0.02 ­0.28 ­0.25 ­0.22 ­0.25 ­0.15 ­0.12 ­0.19 ­0.32 ­0.54 ­0.24Jan 06 ­0.26 ­0.15 ­0.23 ­0.14 ­0.13 ­0.19 ­0.52 ­0.07 ­0.11 ­0.21 ­0.12 ­0.19Feb 06 ­0.41 ­0.13 ­0.23 ­0.41 ­0.38 ­0.23 ­0.75 ­0.38 ­0.46 ­0.39 ­0.29 ­0.37Mar 06 ­0.22 ­0.44 ­0.24 0.32 ­0.56 ­0.77 ­0.58 ­0.08 ­0.44 ­0.36 ­0.35 ­0.34Apr 06 ­0.13 ­0.11 ­0.13 ­0.09 ­0.15 ­0.10 ­0.05 ­0.09 ­0.08 ­0.12 ­0.12 ­0.11May 06 0.04 ­0.02 0.02 0.05 ­0.02 ­0.03 ­0.02 0.01 0.00 ­0.09 ­0.17 ­0.02June 06 0.84 1.00 0.99 1.10 1.15 1.25 1.22 0.80 0.92 0.80 0.88 0.99Jul­06 1.59 0.10 0.97 0.69 1.55 0.28 0.30 0.46 0.27 0.43 0.39 0.64Aug­06 0.53 0.41 0.57 0.51 0.45 0.57 0.47 0.45 0.55 0.51 0.49 0.50Sep­06 0.22 ­0.81 0.04 ­0.79 ­0.59 1.60 0.70 ­0.61 1.16 1.18 1.49 0.33Oct­06 0.43 0.46 0.30 0.26 0.24 0.02 0.02 0.31 0.23 0.11 0.10 0.23Nov­06 ­0.63 ­0.35 ­0.42 ­0.26 ­0.27 ­0.77 ­0.46 ­0.41 ­0.78 ­0.57 ­0.27 ­0.47Table 4.16 Mean monthly water table fluctuations averaged over twoyears 2005 <strong>and</strong> 2006 for Olakara <strong>and</strong> KavallurMonthsMean monthly water table fluctuation (m)Olakara57KavallurJanuary ­0.161 ­0.191February ­0.348 ­0.367March ­0.384 ­0.336April ­0.023 ­0.108May ­0.193 ­0.094June 0.871 1.340July 1.368 0.915August 0.240 0.046September 0.648 0.268October 0.373 ­0.267November ­0.347 ­0.189December ­0.221 ­0.240

16001400120010008006004002000­200­400­600Jan Feb Mar Apr May JunOlakaramonthRainfallFluctuation(mm)Jul Aug Sep Oct Nov DecFig.4.6 Monthly rainfall <strong>and</strong> water table fluctuations at Olakaraduring 2005 to 200616001400120010008006004002000­200­400­600KavallurRainfall(mm)Water tablefluctuation(mm)Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecFig. 4.7 Monthly rainfall <strong>and</strong> water table fluctuations at Kavallurduring 2005 <strong>and</strong> 2006The mean monthly water table fluctuations for the sites of Olakara <strong>and</strong>Kavallur are given in Tables 4.17 <strong>and</strong> 4.18. From the tables, it can beseen that there was a rise in water table from June to September inKavallur. Maximum water table fluctuation was observed in the monthsof June <strong>and</strong> July, that is, 1.368 m. After November, there was a loweringof the water table. Highest decrease in water table was observed betweenthe months of February <strong>and</strong> March which accounted for 0.384 m.At Olakara the rise in water table was observed from June to October.Maximum rise in water table was recorded between the months of May<strong>and</strong> June that is 1.340 m. The highest decrease in water table wasrecorded between the months of January <strong>and</strong> February.58

Table 4.17 Mean seasonal change in water table at OlakaraWell No.Betweenpremonsoon <strong>and</strong>monsoonBetween monsoon<strong>and</strong> post monsoon59Between postmonsoon <strong>and</strong>monsoonOW­1 2.01 ­0.71 ­1.31OW­2 1.12 ­1.04 ­0.07OW­3 1.85 0.10 ­1.95OW­4 2.00 0.67 ­2.67OW­5 1.23 ­0.27 ­0.96OW­6 2.75 ­0.11 ­2.64OW­7 1.84 ­1.36 ­0.48OW­8 2.22 0.51 ­2.73Mean 1.88 ­0.28 ­1.60Table 4.18 Mean seasonal change in water table at Kavallur (m)Well No.BetweenPremonsoon <strong>and</strong>monsoonBetween Monsoon<strong>and</strong> post monsoonBetween Postmonsoon <strong>and</strong>monsoonKW­1 2.60 ­0.93 ­1.67KW­2 1.05 ­0.30 ­0.75KW­3 2.24 ­0.96 ­1.28KW­4 1.72 ­1.01 ­0.71KW­5 1.91 ­1.10 ­0.81KW­6 2.37 ­1.27 ­1.10KW­7 1.97 ­0.83 ­1.14KW­8 1.25 ­0.55 ­0.70KW­9 1.98 ­0.80 ­1.18KW­10 2.31 ­1.14 ­1.17KW­11 2.33 ­1.15 ­1.18Mean 1.98 ­0.91 ­1.06Seasonal changes in mean water table fluctuations at Olakara <strong>and</strong> Kavallurwatersheds were calculated between pre­monsoon <strong>and</strong> monsoon. Seasonalrise in water table was in the range of 1.12 m to 2.22 m at Olakara, whilein Kavallur, the rise in water table was in the range of 1.05 m to 2.60 m.The tendency of decreasing the water table is found between monsoon <strong>and</strong>post monsoon <strong>and</strong> post monsoon <strong>and</strong> monsoon seasons for both sites.The graph gives the fluctuation of ground water table for the entire period.Both the sites show almost similar trend in the fluctuation of the groundwater table.

The correlation between the rainfall <strong>and</strong> water table fluctuation has beenestablished <strong>and</strong> the regression equations depicting the relationship aregiven Fig. 4.8 <strong>and</strong> Fig. 4.9.Water table Fluctuation2000Fluctuation(mm)150010005000­500­1000Apr 05May 05Jun 05Jul 05Aug 05Sept 05Oct 05Nov 05OlakaraKavallurDec 05Jan 06Feb 06Mar 06Apr 06May 06June 06Jul­06Aug­06Sep­06Oct­06Nov­06MonthFig. 4.8 Water table fluctuations at Olakara <strong>and</strong> Kavallur during 2005 <strong>and</strong> 20061500Olakara y = 2.5431x ­ 363.7R 2 = 0.78091500Kavallury = 2.3545x ­ 413.49R 2 = 0.8784Fluctuation(mm)100050000 100 200 300 400 500 600 700­500Rainfall(mm )Water tablefluctuation(mm)100050000 100 200 300 400 500 600 700­500­1000rainfall(mm)Fig.4. 9 Graphs showing the correlation between rainfall <strong>and</strong> water tablefluctuations at Olakara <strong>and</strong> KavallurKavallur Y=2.345X­413.49 R 2 =0.88; Olakara Y=2.5431X­363.7 R 2 =0.78Both sites show a significant relation between rainfall <strong>and</strong> water tablefluctuation.4.4 Water level in Peechi ReservoirMonthly average water levels in Peechi reservoir for the years 2000 to2006 are shown in Fig. 4.10. It may be noted that the maximum waterlevel in the Peechi reservoir is 80 m. The maximum water level is usuallyachieved during the month of August, which is retained till December.The level falls afterwards, which is due to the lack of inflow from thecatchment area as well as releasing of water for irrigation purpose.60

M o n t h l y a v e r a g e wa t e r l e v e l i n P e e c h iR e se r v oi r a b o v e M S L in 2 0 0 0M o nt h l y a v e r a g e wa t e r l e v e l i n P e e c h iR e se r v o i r a bo v e M S L i n 2 0 0 190.0080.0070.0060.0050.0040.0090.0080.0070.0060.0050.0040.0030.0030.0020.0020.0010.0010.000.00j an f eb mar apr may j un j ul aug sep oct nov dec0.00j an f eb mar apr may j un j ul aug sep oct nov decM o nt hsM on t hsHeightM o nt hly aver ag e w at er level in Peechi R eser vo ir90.00ab o ve M SL in 2 0 0 280.0070.0060.0050.0040.0030.0020.0010.00M o nt hly aver ag e w at er level in Peechi R eser vo irab o ve M SL i n 2 0 0 390.0080.0070.0060.0050.0040.0030.0020.0010.000.00j an f eb mar apr may j un j ul aug sep oct nov decMonths0.00M o nt hs90.0080.0070.0060.00M o nt hly av era ge wat e r lev el in P e ec hiR e se rvo ir a bo v e M S L in 20 0490.0080.0070.0060.00M o nt hl y aver ag e w at er level in Peechi R eser vo irab o ve M SL in 2 0 0 5Height50.0040.0030.0020.0010.00Height50.0040.0030.0020.0010.000.00j an f eb mar apr may jun j ul aug sep oct nov dec0.00MonthsMonthsM o n t h ly a v e r a g e wa t e r l e v e l i n P e e c h i90R e se r v o ir a b o v e M S L in 2 0 0 680706050403020100j an f eb mar apr may j un j ul aug s ep oc t nov decM ont hsFig. 4.10 Monthly average water level in Peechi Reservoir for the years 2000­0661

However, from the water level data recorded for six years, it is clear that thereservoir is able to hold the water level usually at 70 m or slightly less than that.4.5 Temperature <strong>and</strong> Relative HumidityData loggers for measuring daily temperature <strong>and</strong> relative humidity wereinstalled at both watersheds. Data were collected from both sites duringJanuary 2005­December 2006. Graphs showing the details are given inFig. 4.11<strong>and</strong> Fig. 4.1250.0Ola k a r a 2 0 0 5MaximumMinimumAverageK a v a l l ur 2 0 0 5MaximumMinimumAverage40.030.020.050.040.030.020.010.010.00.00.0M ont hsm o nt hsFig. 4.11 Maximum, minimum <strong>and</strong> average temperature at Olakara <strong>and</strong>Kavallur during 200540.0Kavallur 2006MaximumMinimumAverage40.0Olakara 2006MaximumMinimumAverage35.035.0Temperature ( 0 c)30.025.020.015.010.05.0Temperature ( 0 c)30.025.020.015.010.05.00.0Jan­06Feb­06Mar­06Apr­06May­06Jun­06Jul­06Aug­06MonthsSep­06Oct­06Nov­06Dec­060.0Jan­06Feb­06Mar­06Apr­06May­06Jun­06Jul­06Aug­06MonthsSep­06Oct­06Nov­06Dec­06Fig. 4.12 Maximum, minimum <strong>and</strong> average temperature at Olakara <strong>and</strong>Kavallur during 200662

During 2005, the maximum temperature at Olakara watershed wasrecorded as 35.3 0 C in May <strong>and</strong> minimum as 20.1 0 C in January. Theaverage temperature ranged between 24.4 0 C <strong>and</strong> 29.0 0 C during the year.In 2006, maximum temperature was recorded as 33.2 0 C in Marchwhereas minimum was 19.8 0 C in January. However the averagetemperature was between 24.7 0 C <strong>and</strong> 28.0 0 C. Maximum temperatureduring 2005 was recorded as 43.4 0 C at Kavallur in May, whereas it was36.0 0 C in February 2006. Minimum temperature recorded was 20.8 0 C inJanuary 2005 <strong>and</strong> 21.4 0 C in January 2006. The average temperatureranged between 26.8 0 C <strong>and</strong> 31.8 0 C during 2005 <strong>and</strong> 25.8 0 C <strong>and</strong> 29.0 0C for the year 2006.4.6 Seasonal distribution of temperatureData on seasonal distribution of temperature are given in Table 4.19. Thetable shows that temperature at Olakara is less than that of Kavallur.Hence forests are probably helping to regulate the microclimate to a greatextent.Table 4.19Seasonal distribution of temperature at Olakara during 2005 <strong>and</strong>2006OlakaraKavallurSeasons Max. Temp. Min. Temp. Max. Temp. Min. Temp.Pre monsoon 33.3 23.1 37.1 24.8Monsoon 27.8 22.6 33.5 23.9Post monsoon 29.4 21.0 34.2 22.6From the Table it may be noted that for both the watersheds themaximum temperature experienced was during premonsoon season. Thetemperature was lower during monsoon season. Temperaturesexperienced in all seasons at Olakara are less than that of Kavallur.63

4.7 Relative HumidityData on relative humidity collected from both sites during January 2005­December 2006 are given in Fig. 4. 13 <strong>and</strong> Fig. 4.14.At Olakara maximum relative humidity was in the range of 88.2 ­95.2 percent during 2005 <strong>and</strong> 84.2­94.4 per cent during 2006. Minimum relativehumidity (RH) recorded was in the range of 56.3­82.5 per cent during2005 <strong>and</strong> 55.2­83.7 per cent during 2006. Maximum humidity at Kavallurranged from 85.4 per cent to 94.2 per cent during 2005 <strong>and</strong> 84.2 per centto 94.3 per cent during 2006. Minimum humidity ranged from 54.2 per centto 80.7 per cent during 2005 <strong>and</strong> 54.3 per cent to 81.2 per cent in 2006.Seasonal distribution of relative humidity was calculated <strong>and</strong> given inTable 4.20. From the Table 4.20, it can be seen that both sites showedalmost similar range of relative humidity during the study period, butOlakara showed slightly higher values when compared to those ofKavallur. This could be due to the presence of forests in Olakaracompared to the more open agricultural ecosystem at Kavallur.100.090.080.070.060.050.040.030.020.010.00.0Ola k a r a 2 0 0 5MaximumMinimumAverage100.090.080.070.060.050.040.030.020.010.00.0K a v a l l ur 2 0 0 5MaximumMinimumAverageM on t hsM o n t h sFig. 4.13 R.H. measured at Olakara <strong>and</strong> Kavallur during 200564

100.0Olakara 2006MaximumMinimumAverage10 0 . 0K av a l l ur 20 0 6MaximumMinimumAverage90.09 0 . 0Relative Humidity (%)80.070.060.050.040.030.020.010.00.08 0 . 07 0 . 06 0 . 05 0 . 04 0 . 03 0 . 02 0 . 010 . 0Jan­06Mar­06May­06Jul­06Sep­06Nov­060 . 0MonthsM on t hsFig. 4.14 R.H. measured at Olakara <strong>and</strong> Kavallur during 2006Table 4.20 Seasonal distribution of relative humidity calculated from the datafor 2005 <strong>and</strong> 2006SeasonOlakaraKavallurMax. RH Min. RH Max. RH Min. RHPre monsoon 87.5 60.2 86.0 57.3Monsoon 93.9 81.0 92.9 79.3Post monsoon 90.6 69.5 89.2 67.8Section 2 Discussion4.8 Discussion<strong>L<strong>and</strong></strong>use pattern studied in the Karuvannur river basin shows that theupstream areas are mostly covered by moist deciduous forests <strong>and</strong> thedownstream locations have been occupied by tree plantations <strong>and</strong> annualagricultural crops. An analysis of the river basin in this study has shownthat during a period of eight years (from 1996 to 2004), the l<strong>and</strong> areaunder agriculture has been increased from 41 per cent to 61 per cent atthe cost of forest l<strong>and</strong>, which showed a corresponding decrease in thearea from 59 per cent to 39 per cent. Thus the forest area has decreased65

at the rate of 2.5 per cent a year. This large scale decrease in forest areaforces us to ask the question, if the l<strong>and</strong>use change has affected the wateryield in the river basin.An examination of the rainfall data for the river basin at three representativestations from 1966 onwards reveals that there is no indication for thedecrease in rainfall. However, yearly variations do occur, which is not anabnormal situation. The river flow discharge observed from 1963 alsoreveals that there is no tendency for <strong>its</strong> decrease during the entire period.Here also, there are some irregular fluctuations from year to year.The linkage between l<strong>and</strong>use change <strong>and</strong> water yield has been reviewed inthe past by several investigators (Bosch <strong>and</strong> Hewlett 1982, Bruijnzeel,1990 <strong>and</strong> 2004, Wilk 2000). The above authors present solid evidencefrom all climatological regions that forest removal will cause an initialincrease in total annual streamflow. This is due to the reduction intranspiration <strong>and</strong> interception. However, as new vegetation grows in <strong>its</strong>place, the change in water yield is lessened. The final change in wateryield is dependent on the evapotranspiration characteristics of the newvegetation in relation to the old, the soil depth <strong>and</strong> fertility which changeswith time <strong>and</strong> the degree of soil <strong>and</strong> undergrowth disturbance during <strong>and</strong>after conversion. If the forest is replaced with plantation forest, the finalchange in water yield will be small. For example, in Kenya, where bambooforest was replaced by pine wood plantations, an initial increase in wateryield disappeared with the onset of pine maturation.In the Karuvannur river basin, the conversion of the forest area intoagricultural l<strong>and</strong> has been occurring at a slow pace all through, thoughwe have satellite map evidences for eight years only. In spite of this, it issurprising that we do not see any evidence for decrease or change in theyearly discharge observed at different locations. Permanent changes instreamflow have been recorded in studies where forests were replaced byagricultural holdings. In Tanzania, Zambia <strong>and</strong> Malaysia, such a changehas resulted in increased water yield (Edwards, 1979; Mumeka, 1986,66

<strong>and</strong> Abdul Rahim, 1988). Although the change in water yield is notapparent when we consider the Karuvannur river basin as a whole, thechange is very much pronounced when the two micro watersheds –Olakara <strong>and</strong> Kavallur are taken individually. Kavallur with apredominantly agricultural l<strong>and</strong>use shows almost 165 per cent of therainfall going out as surface runoff <strong>and</strong> base flow combined in the monthof August during two consecutive years of measurement. This was only 81per cent of the rainfall in Olakara, which was a forested micro watershed.This is in spite of the similarity in rainfall in both the watersheds.Thus, from the previously cited reviews <strong>and</strong> the present study, it appearsthat there is a strong case of reduced annual water yield under forestcover as opposed to cleared or cropped l<strong>and</strong>. However, most of the studieshave been conducted on small watersheds. When we consider largerbasins having a variety of l<strong>and</strong>use types, different l<strong>and</strong> managementpractices <strong>and</strong> vegetation of different species at various stages of growth,the fluctuation in water yield is difficult to notice (Bruijnzeel, 1990). It isprobably because of this reason that the Karuvannur river basin does notshow any consistent fluctuation in water yield. Streamflow changes couldnot be detected in catchments ranging from 7 to 727 km 2 in China after a30 per cent loss in forest (Qian, 1983) <strong>and</strong> in a catchment of 14500 km 2in northern Thail<strong>and</strong> after 40­50 per cent removal of forest (Dyhr­Nielsen,1986) <strong>and</strong> the agriculture replacing four northern Thai catchments since1950 (Alford, 1992). In large catchments, forest conversion is a gradualprocess although the change in forest cover may seem very large.Especially in a river basin such as Karuvannur, felling of trees <strong>and</strong>removal of forests must have been quickly replaced by plantations <strong>and</strong>agriculture, which can buffer the hydrological changes.<strong>L<strong>and</strong></strong>use changes <strong>and</strong> dry season flowObservations in the Karuvannur river basin from 1974 to 1982 show thatthere is no discharge from the river as observed at Pazhoor (CWRDM,1995) during January to May (5 months). In the micro watershed67

observations, it may be noted that there is no streamflow at Olakara fromJanuary to April (4 months) <strong>and</strong> no streamflow in Kavallur fromDecember to April (5 months) during 2005 to 2006. This means that thebaseflow stops soon after the monsoons. In the forested watershed atOlakara, it seems that the baseflow persists till December in contrast withthe Kavallur watershed, where it stops in November <strong>its</strong>elf.The change in baseflow due to removal of forests from different places israther conflicting. For example, Myers (1986) has reported that as a resultof loss of forest cover, the major rivers of tropical Asia now tend to releaserainy season water in floods, followed by extended period of lowstreamflows. However, a study from Malaysia involving transition fromindigenous forest to oil palm plantations showed significantly increasedbaseflow (Abdul Rahim, 1987). A South African study shows decreasedbaseflow when a grassl<strong>and</strong> was reforested with pine trees (Bosch, 1979).These conflicting results could be interpreted in terms of altered soilinfiltration conditions <strong>and</strong> evapotranspiration rates. For example, forestedcatchments with several layers of litter will provide high water infiltration<strong>and</strong> storage compared to soils without organic matter (Pritchett, 1979).Likewise, replacing indigenous forests with exotic species such aseucalypts with deep rooting system can considerably increase the waterloss due to evapotranspiration (Kallarackal <strong>and</strong> Somen, 1997). In thepresent study site at Olakara, the indigenous forest is a moist deciduousforest, which will start leaf shedding in November <strong>and</strong> remain leafless tillend of March. This could be the reason for slightly prolonged baseflow atOlakara compared to Kavallur. However, it is surprising that there is nobaseflow from the leafless moist deciduous forest watershed duringJanuary to March in spite of the negligible evapotranspiration during thisperiod <strong>and</strong> the presence of soil with relatively rich litter content <strong>and</strong> witha relatively high rainfall during the monsoons. However, the slightly moresustained streamflow at Olakara as compared to Kavallur favours the ideaof a forested catchment as compared to predominantly agriculturalcatchment. In spite of this, the water table depth <strong>and</strong> fluctuations at boththe watersheds were more or less similar.68

The ReservoirKaruvannur river basin is characterized by the presence of the Peechireservoir in the upstream location. This reservoir is functional since 1959.From studies conducted on this reservoir it is known that this water bodygets silted at the rate of 0.9 per cent every year (Ratheesh, 2006). Sincemost of the catchment areas of this reservoir is forested, the rate of siltingshould be assumed as lower compared to other reservoirs where thecatchment areas are predominantly agricultural. From the water leveldata collected during 2000 to 2006, it may be noticed that the reservoirreaches <strong>its</strong> maximum storage capacity after the Southwest monsoon <strong>and</strong>this level is maintained till December due to the baseflow. During the dryseason (January to April), this reservoir supplies water for irrigating theagricultural l<strong>and</strong> downstream. Presently, the city of Thrissur <strong>and</strong> some of<strong>its</strong> suburban villages are getting their drinking water supply from thisreservoir.Much debate has occurred on the environmental impacts of dams <strong>and</strong>reservoirs. In spite of all these environmental impacts, hydrologically thePeechi reservoir is a success. As observed from the baseflow data, there isno baseflow from even the forested watershed (Olakara). This means thatthe Manali river across which the Peechi dam has been constructed wouldhave been dry during the summer months. Construction of this dam hascreated a fairly large reservoir, which would satisfy the potable <strong>and</strong>agricultural water requirement of the Karuvannur river basin at leastpartially. Silting <strong>and</strong> sedimentation are the worst threats of dams inmonsoonal locations. Further expansion of agriculture <strong>and</strong> annualcropping of the catchment area should be discouraged to the maximum.High priority should be given for the protection of the forests in theupstream locations of the Peechi reservoir.This study also raises an important issue related to the capacity of amoist deciduous forest (MDF) to help in the streamflow during the dryperiod. In a MDF, evapotranspiration will be negligible during dry part of69

the year, due to the shedding of leaves <strong>and</strong> hence watershed with MDF isexpected to generate much baseflow. However, in the present situation, itis not true. The baseflow will be lasting only till December, leaving thefollowing four months rather dry. This situation calls for further studieson this matter <strong>and</strong> also requires means of conserving water in suchlocations. This is all the more important, as many of Kerala’s river basinsexperience this kind of water shortages during the dry months.70

Chapter 5EFFECTS OF LAND USE/CROPPING PATTERN CHANGES ONVEGETATION, SEDIMENTATION AND SOCIO­ECONOMIC CONDITIONSOF THE PEOPLEIt is often said that unsound agricultural activities in the upl<strong>and</strong> areasdeplete vegetation, augment sedimentation <strong>and</strong> affect socio­economicconditions of the people. This chapter deals with effects of l<strong>and</strong>use/cropping pattern changes on vegetation, sedimentation <strong>and</strong> socioeconomicconditions of the people.5.1 Plant diversity in the Olakara watershed areaThe vegetation in the Olakara watershed area is Southern moist mixeddeciduous forests. The dominant trees in this forest area are Terminaliapaniculata, T. crenulata, Schleichera oleosa, Lagerstroemia microcarpa,Bombax insigne, Grewia tiliifolia, Dillenia pentagyna, Hymenodictyonorixense, Xylia xylocarpa etc. The lower staratum trees consist of Naringicrenulata, Catunaregam spinosa, Cordia wallichii, Careya arborea,Sterculia urens,Helicteres isora, among other. Species in the evergreenforests such as Aporosa cardiosperma, Carallia brachiata, Hydnocarpuspent<strong>and</strong>ra, Stereospermum colais etc. are common along the side streams<strong>and</strong> other moisture rich area with other shrubaceous members. Acaciacaesia, A. torta, Spatholobus parviflorus, Dalbergia volubilis are thecommon woody climbers in the area. Undergrowth is thick with herbs <strong>and</strong>shrubs. Gregarious tropical weeds such as Lantana camara <strong>and</strong>Chromolaena odorata form thickets in many areas. Another exotic weedHyptis capitata is getting established in the forests especially along thesides of the watercourses. Diversity of fern is low; Adiantum <strong>and</strong>Selaginella spp. are the common terrestrial ferns in the area. However, anepiphytic fern Drynaria quercifolia is common on the trees. Orchiddiversity, both terrestrial <strong>and</strong> epiphytics is low. Cymbidium aloifolium,71

Pholidota imbricata <strong>and</strong> V<strong>and</strong>a testacea are the common epiphytic orchidsin the area. Grasses in the canopy covered areas are relatively few. Thenotable ones are Panicum notatum, Centotheca lappacea, <strong>and</strong> Cyrtococcumoxyphyllum. The endemic wild rice, Oryza officinalis ssp. malampuzhensisis fairly common along the stream sides. In the open rocky areas, exoticgrasses Pennisetum americanum <strong>and</strong> P. pedicellatum are common alongwith the indigenous Ischeamum indicum.Habit wise, 122 herbs, 33 shrubs, 54 climbers <strong>and</strong> 50 trees wereidentified. Among the 259 species enumerated in the area, there are only29 peninsular Indian endemics. This may be due to the habitat <strong>and</strong> lowerelevation of the area. The occurrence of Securinega virosa, Careyaarborea, Catunaregam spinosa etc. indicates that the area was prone toseasonal fire in the past. The list of plants in the watershed is given inAppendix 1.5.2 Vegetation analysisSpecies distribution can be well understood from AB/F ratio (Tables 5.1<strong>and</strong> 5.2). Preponderance of contiguous distribution prevails in Olakarawith a rarity of r<strong>and</strong>om distribution <strong>and</strong> absence of regular distribution ofspecies. Most of the species in Kavallur exhibited r<strong>and</strong>om distributionfollowed by contiguous <strong>and</strong> regular distribution. The distribution patternthat prevails in a given community depends in part on the habitat,including <strong>its</strong> history <strong>and</strong> in part on characteristics of the species in acommunity.The main species distributed contiguously in Olakara area Lagerstroemialanceolata, Lagerstroemia microcarpa, all Terminalia species except T.paniculata, Xylia xylocarpa, <strong>and</strong> Tabernamontana heynearna. The r<strong>and</strong>omdistribution is exhibited by Bombax ceiba, Dillinia pentagyna,Grewiatiliifolia, Sterculia guttata etc. in Olakara area <strong>and</strong> Bombax ceiba , Dilliniapentagyna, Casssia fistula, etc. in Kavallur area. It is also notable that inOlakara area competition between individuals are on a higher scale.72

Table 5.1 Vegetation analysis of OlakaraSI.NoSpecies D FRD(%)RF(%)AB BA(cm²) RBA(%)AB/F1 Xylia xylocarpa 576 92 31.17 13.86 6.26 1276.12 3.52 0.068 48.552 Dillenia pentagyna 212 84 11.47 12.65 2.52 1070.02 2.95 0.030 27.073 Terminalia paniculata 216 72 11.69 10.84 3.00 1408.65 3.89 0.042 26.424 Grewia tilifolia 132 52 7.14 7.83 2.54 1244.71 3.43 0.049 18.415 Lagerstroemia microcarpa 92 36 4.98 5.42 2.56 1201.74 3.32 0.071 13.726 Terminalia crenulata 24 12 1.30 1.81 2.00 3050.62 8.42 0.167 11.527 Bombax ceiba 56 32 3.03 4.82 1.75 1058.53 2.92 0.055 10.778 Cleistanthus collinus 76 24 4.11 3.61 3.17 757.40 2.09 0.132 9.829 Tectona gr<strong>and</strong>is 40 16 2.16 2.41 2.50 1828.16 5.04 0.156 9.6210 Lagerstroemia lanceolata 80 12 4.33 1.81 6.67 863.68 2.38 0.556 8.5211 Sterculia guttata 32 28 1.73 4.22 1.14 872.82 2.41 0.041 8.3612 Ficus tjakela 4 4 0.22 0.60 1.00 2436.08 6.72 0.250 7.5413 Dalbergia latifolia 4 4 0.22 0.60 1.00 2325.99 6.42 0.250 7.2414 Macaranga peltata 44 20 2.38 3.01 2.20 619.82 1.71 0.110 7.1015 Pterocarpus marsupium 8 8 0.43 1.20 1.00 1801.72 4.97 0.125 6.6116 Terminalia chebula 8 8 0.43 1.20 1.00 1777.86 4.91 0.125 6.5417 StereospermumchelenoidesIVI16 16 0.87 2.41 1.00 1051.99 2.90 0.063 6.1818 Albizia odoratissima 12 4 0.65 0.60 3.00 1559.09 4.30 0.750 5.5519 Terminalia bellarica 12 8 0.65 1.20 1.50 1289.73 3.56 0.188 5.4120 Cassia fistula 4 4 0.22 0.60 1.00 1649.45 4.55 0.250 5.3721 Schleichera oleosa 16 8 0.87 1.20 2.00 1145.45 3.16 0.250 5.2322 Stereospermum collais 24 20 1.30 3.01 1.20 220.64 0.61 0.060 4.9223 Sapindus sp. 16 16 0.87 2.41 1.00 286.36 0.79 0.063 4.0724 Holarhena pubascens 24 16 1.30 2.41 1.50 120.99 0.33 0.094 4.0425 Haldinia cordifolia 8 4 0.43 0.60 2.00 927.82 2.56 0.500 3.6026 Hydnocarpus pent<strong>and</strong>ra 4 4 0.22 0.60 1.00 962.50 2.66 0.250 3.4727 Bauhinia malabarica 16 8 0.87 1.20 2.00 483.95 1.34 0.250 3.4128 Garuga pinnata 4 4 0.22 0.60 1.00 927.82 2.56 0.250 3.3829 Cleistanthus sp. 24 4 1.30 0.60 6.00 275.34 0.76 1.500 2.6630 Wrightia tinctoria 4 4 0.22 0.60 1.00 459.45 1.27 0.250 2.0931 Caryota urens 12 4 0.65 0.60 3.00 276.90 0.76 0.750 2.0232 Careya arborea 8 8 0.43 1.20 1.00 105.97 0.29 0.125 1.9333 Kydia calicina 12 4 0.65 0.60 3.00 215.09 0.59 0.750 1.8534 Ziziphus oenoplia 8 4 0.43 0.60 2.00 267.59 0.74 0.500 1.7773

35 Acasia instia 4 4 0.22 0.60 1.00 86.63 0.24 0.250 1.0636 Bischofia javanica 4 4 0.22 0.60 1.00 86.63 0.24 0.250 1.0637 Ficus drupaceae 4 4 0.22 0.60 1.00 86.63 0.24 0.250 1.0638 Olea dioica 4 4 0.22 0.60 1.00 81.45 0.22 0.250 1.0439 Tabernamontanaheyneana4 4 0.22 0.60 1.00 81.45 0.22 0.250 1.04Total 1848 664 100 100 80 36242.8 100 10.3 300D = Density; F = Frequency; RD = Relative Density; RF = Relative Frequency; AB = Abundance;BA = Basal Area; RBA = Relative Basal Area; IVI = Importance Value Index** Maturity index = 17.03Table 5.2 Vegetation analysis of KavallurSI.No Species D FRD(%)74RF(%)AB BA(cm²) RBA(%)AB/F1 Ficus tjakela 40 40 2.78 5.41 1.00 7943.09 21.82 0.025 30.012 Macaranga peltata 260 80 18.06 10.81 3.25 389.77 1.07 0.041 29.943Lagerstroemiamicrocarpa120 60 8.33 8.11 2.00 3469.09 9.53 0.033 25.974 Terminalia paniculata 140 40 9.72 5.41 3.50 3310.36 9.10 0.088 24.225 Xylia xylocarpa 160 40 11.11 5.41 4.00 2329.39 6.40 0.100 22.926 Grewia tilifolia 100 60 6.94 8.11 1.67 2853.48 7.84 0.028 22.897 Dillenia pentagyna 40 40 2.78 5.41 1.00 5071.52 13.93 0.025 22.128 Hydnocarpus pent<strong>and</strong>ra 60 20 4.17 2.70 3.00 4159.31 11.43 0.150 18.309 Erythrena indica 80 60 5.56 8.11 1.33 1272.91 3.50 0.022 17.1610 Macaranga peltata 100 40 6.94 5.41 2.50 235.40 0.65 0.063 13.0011 Aporusa lindleyana 40 40 2.78 5.41 1.00 1354.68 3.72 0.025 11.9112 Bombax ceiba 60 40 4.17 5.41 1.50 467.55 1.28 0.038 10.8613 Sterculia guttata 20 20 1.39 2.70 1.00 1935.82 5.32 0.050 9.4114 Cassia fistula 40 40 2.78 5.41 1.00 206.90 0.57 0.025 8.7515Tabernamontanaheyneana60 20 4.17 2.70 3.00 110.87 0.30 0.150 7.1716 careya arborea 20 20 1.39 2.70 1.00 876.99 2.41 0.050 6.5017 Caryota urens 40 20 2.78 2.70 2.00 103.09 0.28 0.100 5.7618 Carica pappaya 20 20 1.39 2.70 1.00 168.32 0.46 0.050 4.5519 macaranga peltata 20 20 1.39 2.70 1.00 91.95 0.25 0.050 4.3420 Cleistanthus collinus 20 20 1.39 2.70 1.00 45.82 0.13 0.050 4.22Total 1440 740 100 100 36.75 36396.31 100 1.161 300D = Density; F = Frequency; RD = Relative Density; RF = Relative Frequency; AB = Abundance;BA = Basal Area; RBA = Relative Basal Area; IVI = Importance Value Index** Maturity index = 37.00IVI

5.3 SedimentationThe total rainfall in the months of July, August <strong>and</strong> October 2005 were665,102 <strong>and</strong> 112 mm, respectively while that in June, August <strong>and</strong>September 2006 were 538, 304 <strong>and</strong> 296 mm respectively. The meanvalues of sediment yield estimated from the watershed are shown in Table5.3. The nutrient contents in the sediments are presented in Table 5.4.The mean sediment production estimated by measuring the flow of waterfrom the watershed was 1335, 4363 <strong>and</strong> 1152 g during July, August <strong>and</strong>October 2005, respectively. In the months of June, August <strong>and</strong> September2006 corresponding mean values were 932, 2104 <strong>and</strong> 973 g. This is froman area of 1.22 km 2 . This indicates that the maximum sediment yield wasin the month August, 2005 (4363.2 g) <strong>and</strong> there was much variation inthe months of June (133.5 g) <strong>and</strong> October, 2005 (1152 g). In the year2006, the maximum sediment yield was in the month of August (2104 g).There was not much difference in the sediment yield during the months ofJune <strong>and</strong> September, 2006. The general pattern with respect to thesediment yield is same, the maximum being in the month of August inboth the years 2005 <strong>and</strong> 2006.The nutrient contents in the sediments during the above periods were1.725, 2.081, 1.532 g/ha of nitrogen, 0.72, 1.38, 0.68 g/ha ofphosphorus <strong>and</strong> 1.16, 1.89 <strong>and</strong> 1.05 g/ha of potassium in the months ofJuly, August <strong>and</strong> October 2005 respectively. In 2006, the nutrientsremoved through the sediments in the months of June, August <strong>and</strong>September were 1.263, 1.642, 1.361g/ha of nitrogen, 0.54, 1.12, 0.63g/ha of phosphorus <strong>and</strong> 0.96, 1.47 <strong>and</strong> 1.07g/ha of potassiumrespectively.Converting the sediment yield/ ha basis, it was 10.90 g, 35.75 g <strong>and</strong> 9.44g/ha in the months of June, August <strong>and</strong> October, 2005 (the weight of1.22 km 2 soil is 268.4 million kg). In the year 2006, the sediment yieldwas 7.64, 17.25 <strong>and</strong> 8.0 g/ha in June, August <strong>and</strong> September,75

espectively. This shows that during the period 2005 to 2006, 88.98 g/haof sediment was produced. This is from a small area where thedisturbance is very low <strong>and</strong> is totally protected.Table 5.3 Sediment yield estimated from the watershedYear/ month2005Yield1.22 km 2 (g) Per ha (g)July 1335.00 10.90August 4363.20 35.75October 1152.00 9.442006June 932.00 7.64August 2104.00 17.25September 973.00 8.00Table 5.4 Sediment yield estimated from the watershed <strong>and</strong> the nutrientcontentsYear/ monthYieldNutrients g/haper ha (g) N P K2005July 10.90 1.725 0.72 1.16August 35.75 2.081 1.38 1.89October 9.44 1.532 0.68 1.052006June 7.64 1.263 0.54 0.96August 17.25 1.642 1.12 1.47September 8.00 1.361 0.63 1.07The relationship between sediment yield <strong>and</strong> rainfall is shown in Table 5.5. Itcould thus be seen that the maximum sediment yield occurred in themonth of August in 2005 <strong>and</strong> 2006. This showed a pattern in which theyield is maximum, immediately after a heavy rainfall followed by a sudden76

decrease. Usually high sediment yield is expected where the rainfall ismaximum. But, highest values were recorded immediately after theoccurrence of heavy rain fall. This indicates that during heavy splash, thesoil becomes loose <strong>and</strong> is transported later. When the rain recedes in themonth of September in both years, the transport of materials declines.Table 5.5. Relationship between sediment yield <strong>and</strong> rainfallYear/ monthSediment yieldg/ha Rainfall (mm)2005July 10.90 665.8August 35.75 102.4October 9.44 112.82006June 7.64 538.7August 17.25 304September 8.00 296.6Attempt was also made to assess sedimentation in highly degraded parts ofupl<strong>and</strong> area. Unfortunately due to non­co­operation of the local people,data could not be gathered. Thus, to indicate the trend we depend upon astudy by Suresh Kumar (2002) at Bharathamala of Peechi, which is a partof Kavallur area. The study reported high sedimentation in the area. Forinstance, sedimentation was found to be 9675.229 tonnes in August,followed by 7470.739 tonnes in September, but the run­off was maximumduring October. This increased rate of sediment yield during August <strong>and</strong>September is due to the large quantity of soil movement together with thesurface flow at the time of intercultural operations in the cultivable l<strong>and</strong>s.This indicates two things; first, sedimentation is low in a good forest area<strong>and</strong> as degradation increases due to loss of vegetation <strong>and</strong> cultivation,sedimentation also increases. This underscores the need for more vegetationcover in the upl<strong>and</strong> areas, which will prevent sedimentation in the reservoir.77

5.4 Increase of production <strong>and</strong> productivity in agricultural sectorThe traditional agricultural system in the study area was dominated bypaddy­based production system, where production from cultivated cropswas accounted mainly by paddy, followed by coconut, tapioca, banana,<strong>and</strong> vegetables. Crops other than paddy were not attended to intensively,which resulted in poor yields from these crops. Even for coconut, once theseedlings were planted further attention was paid to it only at the time ofharvest. Mango, jack, cashew, tamarind, etc were just natural growth <strong>and</strong>no attention was given. Since cultivation was meant mainly for homeconsumption in the past, monetary income was not the criterion forcropping decisions. The situation has now changed <strong>and</strong> in the presentscenario, cultivation is mainly for income <strong>and</strong> profit generation. Farmerstherefore take special care to select crops <strong>and</strong> crop varieties with betteryields <strong>and</strong> tend them carefully, to obtain better yields. For instance, theyields of coconut, banana, tapioca, <strong>and</strong> pepper doubled during the pasttwo decades. Cashew, though an income­generating crop, had almostbeen replaced by rubber, which generated a more steady <strong>and</strong> higherincome flow. Fruit trees like mango <strong>and</strong> jack were replaced by incomegeneratingcash crops. The overall result was an increase in agriculturalproduction with major shifts in composition from food items tocommercial items (Table 5.6). One disadvantage of this is that the foodsecurity has been reduced significantly.The comparison of productivity of selected crops during 1975­76 <strong>and</strong>2005­06 revealed an increase in the productivity of major crops like paddy,coconut, rubber, <strong>and</strong> tapioca (Table 5.7). Modernization of agriculture withthe adoption of high yielding varieties, mechanization, <strong>and</strong> widespreadapplication of fertilizers, manures <strong>and</strong> pesticides had enabled the increasein the productivity of the crops.78

Table 5.6 Production: A comparative analysis between 2005­06 <strong>and</strong> 1975­76 (kg)Sl. No. CropProduction in Productionin(2005­06)(1975­76)1 Paddy 88506 856732 Coconut (Nos) 62457 531573 Areca nut 376 2804 Pepper 2920 22065 Cashew 1064 24796 Tapioca 127069 7329713 Pulses 1120 95514 Banana 228673 13666715 Ginger 3158 275118 Rubber 30317 18699Table 5.7 Productivity comparison between 1975­76 <strong>and</strong> 2005­06 (Kg/ha)SI. No. CropProductivity in Productivity in2005­061975­ 761 Paddy 2882 21852 Coconut (Nos) 5637 55203 Areca nut 217 2094 Pepper 326 2995 Cashew 760 7406 Pulses 830 7587 Banana 8190 70528 Ginger 3852 36209 Turmeric 2342 22895.5 Socio­economicsAs mentioned earlier, conversion of forest area to agricultural l<strong>and</strong> wasthe main l<strong>and</strong> use change in the study area, which brought aboutchanges in the socio­economic conditions of the people. Table 5.8 givesan overview of major socio­economic conditions of selected farmers79

Table 5.8 Socio­ economic profile of selected farmers1 Sample size 1002 Total population 4513 Average Family size 4.514 Literacy rate 99%5 Total work force 333(74% )6 Work force participation rate 57%7 Total employed person 1888 Female work participation rate 3.559 Male work participation rate 95.3110 House holds fully depended agriculture 29%11 Employed in agriculture 58%12 Employed in service sector 24%13 Average annual income of family Rs.71,29614 Per capita income Rs.15,80915 Annual income from agriculture per household 49,10016 Average savings per family 973117 Average debt per family 57270The family size of the selected farmers was small (4.51). As elsewhere inthe State, the literacy rate was very high (99%). The per capita incomeamounted to Rs. 15809 which was lower than that of state (Rs. 24053)<strong>and</strong> district average (Rs. 25933) during 2004­05 (Government of Kerala,2005). Average savings per family amounted to Rs.9731. However, it wasreported that the average debt (Rs.57270) was more than average familysavings. They borrowed money for agricultural operation, houseconstruction, marriages, etc. Low per capita income, low savings <strong>and</strong> highdebt indicate their poor economic condition.The respondent informed that about 85 per cent of the householdsdepended fully on agriculture for their livelihood during 1975­76. In80

contrast, nearly 29 per cent of the households depended fully onagricultural sector either as cultivators <strong>and</strong>/or as farm labour for theirlivelihood during 2005­06. However, due to an increase in productivity<strong>and</strong> production in the agricultural sector <strong>and</strong> price rise, income fromagriculture has been doubled, that is from Rs. 7267 to Rs. 15809 from1975­76 to 2005­06.Due to increase in population <strong>and</strong> the l<strong>and</strong> reforms, agricultural farms gotsubdivided resulting predominance of very small­sized farms. Since smallsizedfarms are not viable <strong>and</strong> mechanization is not practical in suchfarms, the owners of these farms turned to other occupations for theirlivelihood. For such cultivators farming was only a subsidiary activity whopreferred those crops which required less personal attention.The immediate result of the change in the cropping pattern was thereduction in rice production. Rice­based farming system <strong>and</strong> cattlerearingare inter­dependent activities. Sharp decline in the area under ricereduced the availability of straw, which, in turn, led to reduction in thenumber of draught animals <strong>and</strong> working bullocks in the farm sector. Thiscaused decline in the availability of farmyard manure <strong>and</strong> break down ofthe traditional farming sector. Since most of the farmers preferred to keeprice l<strong>and</strong>s fallow during summer, production of pulses <strong>and</strong> vegetablesdeclined significantly.While increase in the area under cash crops like coconut <strong>and</strong> rubberhelped to increase farm income, changes in cropping pattern in favor ofperennial crops have an immediate <strong>and</strong> direct impact on the employmentpattern in the rural area. The shrinkage of rice cultivation <strong>and</strong> otherseasonal crops has displaced agricultural labour especially women fromthe farm sector (The female work participation rate in the study area wasonly 3.55% ). Although cultivation of perennial crops like coconut <strong>and</strong>rubber required only less number of workers per unit area, increase ofarea under agriculture was not helpful to solve unemployment problem inthe farming sector.81

Chapter 6VALUATION OF WATER RESOURCES AND USE CONFLICTSThe man­made wetl<strong>and</strong>s in the forest ecosystem are water storage areas<strong>and</strong> are classified into (a). Reservoirs holding water for irrigation <strong>and</strong>/orhuman consumption with a pattern of gradual, seasonal, draw down ofwater level <strong>and</strong> (b). Hydro­dams with regular fluctuations in water level ona weekly or monthly basis (Dugan, 1990). Water is often regarded asnaturally existing, freely available commodity. But in reality, since <strong>its</strong>supply in most places is less than <strong>its</strong> dem<strong>and</strong>, it has a value.Conflict over natural resources, particularly water can take place atvarious levels: households, local, regional, societal <strong>and</strong> global. Theintensity <strong>and</strong> impact of conflict over water resources also varies from timeto time <strong>and</strong> place to place. For instance, intensity <strong>and</strong> impact of nonavailabilityof irrigation or drinking water during summer <strong>and</strong> rainyseason <strong>and</strong> also in rural <strong>and</strong> urban areas are different. In this chapter,the results of economic valuation of water resources in Peechireservoir/wetl<strong>and</strong>, problems relating to pricing of water <strong>and</strong> thewillingness to pay expressed by the people for adequate <strong>and</strong> regularsupply of water are presented. The nature <strong>and</strong> extent of water resourceuse conflict in the study area is also discussed.6.1 Direct extractive benef<strong>its</strong>The direct extractive/consumptive benef<strong>its</strong> of Peechi wetl<strong>and</strong> include fish,irrigation <strong>and</strong> drinking water benef<strong>its</strong>. The estimated values of thebenef<strong>its</strong> are presented in Table 6.1. The direct extractive benef<strong>its</strong> from thewetl<strong>and</strong>s amount to Rs. 1110 lakhs with a value of Rs. 3, 232, <strong>and</strong> 875lakhs for fish, irrigation, drinking water use respectively. The drinkingwater users appreciated the wetl<strong>and</strong> benef<strong>its</strong> more than that of theirrigation users in the study area. This may be attributed to the severe83

scarcity of water <strong>and</strong> the burgeoning dem<strong>and</strong> in the urban areas wherethere are no better alternatives.Table 6.1 Value of direct extractive benef<strong>its</strong> from Peechi wetl<strong>and</strong>ParticularsValue (Rs. In lakhs)Fish 3Irrigation 233Drinking water 875Total 1111Value per ha (Rs.) 0.886.2 Direct non­extractive benef<strong>its</strong>The direct non­consumptive/extractive benef<strong>its</strong> of the wetl<strong>and</strong>s weretaken in the study as <strong>its</strong> ecotourism potential. The consumer surpluses ofthe visitors to the Peechi Dam are presented in the ensuing section.6.3 Dem<strong>and</strong> function of tourists of Peechi DamThe dem<strong>and</strong> function estimated for the Dam, presented in Table 6.2,revealed that variables income (X4), opportunity cost of time (X6), travelcost (X 7) distance traveled (X 8) infrastructure (X 9) were statisticallysignificant with expected signs (Table 6.2). The positive sign of thevariable, willingness to pay (X 3) indicates that tourists are willing to payfor the recreational benef<strong>its</strong> enjoyed at the Dam site <strong>and</strong> hence thepresent entrance fee of Rs. 2 per person under estimates the WTP of thevisitor. The fee is much lower as evident from the high consumer surplus.This finding emphasizes that the present fee can be hiked <strong>and</strong> theadditional revenue so generated can be utilized for site improvement.With an increase in income, the WTP of the tourist increases <strong>and</strong> viceversa.84

Table 6. 2 Dem<strong>and</strong> function of tourists of Peechi DamVariable Coefficient t valueConstant0.1635(0.2109)X 10.0056(0.0036)X 20.9399(0.2084)X30.0353(0.0091)0.77521.55554.5100**4.8791**Variable Coefficient t valueX 40.0194(0.0078)X 50.5939(0.6386)X6­0.2176(0.0790)X 7­0.0125(0.0029)X 8­0.2166(0.0515)X90.0191(0.0051)X 10­0.0021(0.0015)2.4871*0.9299­2.7544*­4.3103**­4.2058**3.7450*­1.4000Consumer surplus = Rs. 392 per person per visitR 2 =0.55, F=25.22n=250Total visitors are estimated to be 100000 per annum* Significant at five per cent level of significance** Significant at one per cent level of significanceFigures in parentheses are st<strong>and</strong>ard errors85

6.4 Total recreational valueThe total recreational values of the Dam presented in Table 6.3, show thatrecreation value per unit area of the Dam is Rs. 3136 per hectare.Table 6.3 Total estimated value of tourism in Peechi wetl<strong>and</strong>sParticularsValueRecreation benef<strong>its</strong> of Peechi Dam (Rs. in lakhs) 39.61Total recreation value per hectare (Rs) 31366.5 Indirect use valueThe indirect use values for the wetl<strong>and</strong>s were worked out based on figuresgiven by WWF (2004) since estimation of individual values was beyondthe scope of the study. The figures have been extrapolated to the studysite <strong>and</strong> are presented in Table 6. 4.Table 6.4 Indirect use value of Peechi wetl<strong>and</strong>sEconomic value Rs in lakhs Rs. per hectareFlood Control 264 20880Water Filtering 164 12960Biodiversity 122 9630Habitat Nursery 114 90456.6 Total estimated economic valueBased upon the estimates of different tangible <strong>and</strong> intangible benef<strong>its</strong> theTEV of Peechi wetl<strong>and</strong>s was measured <strong>and</strong> the results are presented inTable 6.5. The estimated value per hectare of the wetl<strong>and</strong>s is Rs. 1.46lakhs with an estimated total value of Rs.1844 lakhs.86

Table 6.5 Total economic value of Peechi wetl<strong>and</strong>sWetl<strong>and</strong> Benef<strong>its</strong>ValueValue(Rs. in lakhs) (Rs. ha –1 )<strong>Use</strong> valuesDirect use values· Direct consumptive use 1111 87948· Direct non consumptive use 40 3136Indirect use valuesFlood Control 264 20880Water Filtering 164 12960Biodiversity 122 9630Habitat Nursery 115 9045Option values 11 799Non­use values 21 1640TEV 1848 1460396.7 Pricing of water: Some issuesIt was beyond the scope of this study to determine the price of watersupplied from Peechi Reservoir. Instead, it is attempted here to comparethe price per unit of water supplied from Peechi <strong>and</strong> <strong>its</strong> costs <strong>and</strong> also todiscuss issues like equity <strong>and</strong> need of fair pricing for better managementof water resources in the study area. The average cost of purification ofPeechi water is very low (below Rs.2 per 1000 liters). As per the estimateof Water Authority, the average cost of purification <strong>and</strong> distribution is Rs.9 per 1000 liters. But, it collects only Rs.2 per 1000 liters. In other words,the water is supplied at a subsidized rate. It is a controversy whetherwater should be supplied at a subsidized rate when <strong>its</strong> supply is limitedcompared to <strong>its</strong> dem<strong>and</strong>. If water is viewed simply as a commodity, itwould be reasonable to expect that it should be priced to cover at least <strong>its</strong>cost of provision so that low value uses are discouraged <strong>and</strong> supplies areavailable for high value users. However, a strict application of this87

principle needs to be h<strong>and</strong>led with some caution to ensure that thepoorest people in the community are not disadvantaged (Agudelo, 2001).There are arguments that subsidy in the water supply ends up in a ‘freewater dilemma’: a situation which ironically results in rich people gettingwater free or very cheaply <strong>and</strong> poor people buying water at excessive ratesor drinking unsafe water (Savenije <strong>and</strong> Zaag, 2002). Our survey highlightsnearly 85 per cent of the people who have water connection from PeechiWater Supply scheme belong to higher <strong>and</strong> middle income groups whoseability to pay for water is more.One of the disadvantages of low pricing of water is that it cannot generateadequate surplus to maintain the distribution system, resulting in <strong>its</strong>frequent breakage of supply of water. The present distribution system(pipes) of Peechi drinking water supply scheme was laid about twodecades back <strong>and</strong> the water supply started in 1986. Primo pipes of 700mm diameter <strong>and</strong> 5.5 m length are used in the scheme. Although the lifespan of the primo pipe is said to be 15 years, it is around 20 years now,since the pipe line has been laid. During the initial period, there were nomajor problems reported regarding breakage of distribution line. Thebreakage problem which started around 8­10 years back has almostbecome a regular <strong>and</strong> major problem during recent years. For instance,this problem occurred about 17 times during 2005­2006 <strong>and</strong> in eachoccasion water supply was delayed about 2­3 days. This was mainly dueto inefficient management <strong>and</strong> inadequate monitor <strong>and</strong> maintenance ofpipes on a timely basis.Since the breakage has to be repaired immediately, the cost of repairing isalso high. For emergency works the labour cost will be more. According tothe officials of Kerala Water Authority, the main expenditure consists ofmaterial <strong>and</strong> labour cost. It is difficult to assess cost of repair per meterlength as it depends on the intensity of breakage, time (if the work is atnight, labour charge will more), place, type of soil etc. An average cost ofreplacement of 5 m length, material cost will be around Rs.28000­3000088

(includes pipe, iron brackets, transportation, etc.). The labour cost will bearound Rs.12000­15000 (includes human labour, machineries etc). Anaverage expenditure of 40000­45000 is expected per case of breaking ofdistribution line. According to the officials of Water Authority, about Rs.7­7.5 lakhs is spent per annum only for the replacement of the brokenpipes.Thus, this necessities the generation of more profit through proper pricingof water which should be based on economic as well as social,environmental <strong>and</strong> technical impacts. In other words, a proper waterpricing policy should be formulated aiming to recover at least a majorportion of cost of providing the supply, get funds for water development,proper allocation <strong>and</strong> resolution of water resource conflict, environmentalbenef<strong>its</strong> <strong>and</strong> dem<strong>and</strong> management (Agudelo, 2001).6.8 Willingness to payThe Kerala Water Authority in Thrissur district mainly provides threecategories in water connection viz., domestic, non­domestic <strong>and</strong> industrialon the basis of the level of consumption <strong>and</strong> charges rates accordingly asshown in Table 6.6.The cost of supplying water depends upon different schemes. Stateaverage is Rs.8/­ to Rs.9/­ per 1000 ltrs. Comparatively it is very low inPeechi as compared to the State average. There is a marginal increase of1000 to 1500 connection per year in Thrissur Water Supply Division.There are 4976 public taps (The old municipality area is excluded) underThrissur Water Supply Division. Out of this, approximately 80 per cent ofpublic taps depends on Peechi as the source of water. There are 1790public taps in old Municipality area which fully depends on Peechi water.Total supply of water through a public tap depends upon the area <strong>and</strong>the season. In some areas <strong>and</strong> seasons, there is continuous watersupply.89

Table 6.6 Categories of water use <strong>and</strong> the charge per 1000 ltrsCategoriesPresent chargeDomesticUp to 10000 ltrs Rs. 20/­+2/­10001 to 30000 Rs. 3/­ 1000 ltrs30001 to 50000 Rs. 5/­ per 1000 ltrsAbove 50000 Rs. 7.35/­ per 1000 ltrsNon­DomesticMinimum charge Rs.102/­Up to 50000 Rs. 7.35/­per 1000 ltrsAbove 50000 Rs. 10.60/­ per 1000 ltrsIndustrialMinimum charge Rs.202/­Above 50000 Rs. 10.60/­ per 1000 ltrsBut, in some other areas it is limited to 4 to 5 hrs. There is no metering incase of public taps <strong>and</strong> therefore no accurate measurement is possibleregarding the total supply of water through public taps. Kerala WaterAuthority collects the charges on public taps from the local authorities­Panchayats/Muncipalities.A survey was conducted among users of drinking water to know theirwillingness to pay for timely <strong>and</strong> adequate water supply. About 80 per centof the samples, who used drinking water from Peechi, were willing to paymore for timely <strong>and</strong> adequate supply of water where as 20 per cent agreedwith the existing price. In the first category, about 60 per cent were willingto pay about Rs 6­8 for 1000 litres of water <strong>and</strong> rest have agreed to payRs. 10­12 on condition that the supply should be regular. The first categoryoffered a higher amount since about 50 per cent of them have no well.Peechi is the main source of drinking water for this category which suffersa lot at the time of breakage of pipes. In the second category, about 80 percent have wells in their house compound <strong>and</strong> water from Peechi is only asupplementary one. This supports charging a fair price for water fromPeechi, as it is essential to reflect <strong>its</strong> value to society as a scarce resource.90

6.9 Water use conflictThe implications of the competition between agricultural use <strong>and</strong>potable/domestic/municipal/industrial use for water quantity <strong>and</strong> qualityare manifold. Urban water supply utilities <strong>and</strong> most industrial concernsare always looking for low volume high quality water whereas irrigatedagriculture seeks high volumes of water <strong>and</strong> is generally indifferent toquality. In addition, the trend to conserve the integrity of natural systems,particularly that of surface water bodies <strong>and</strong> wetl<strong>and</strong>s <strong>and</strong> to maintain aset of in­situ environmental services adds another dimension to thecompetition <strong>and</strong> conflicts for water between multitude of users.There are socio­ecological <strong>and</strong> economic conflicts <strong>and</strong> conflict over naturalresources such as l<strong>and</strong>, water, <strong>and</strong> forests is ubiquitous. Some of thenatural resources provide basic goods without which people cannotsurvive in the world. Thus, people with varied interest <strong>and</strong> socio­economicconditions compete for natural resources to ensure their livelihood whichresults in conflict. A study by FAO (1998) has stated that conflictemerges when the interests of two or more parties clash <strong>and</strong> at least oneof the parties seeks to assert <strong>its</strong> interests at the expense of another party’sinterests. A variety of factors contribute conflict over natural resourcesbut scarcity due to increasing dem<strong>and</strong> <strong>and</strong> environmental degradation isthe most important. Economic theory has provided two reasons whyconflicts emerge over natural resources: a) the allocation of scarceresources requires trade­offs which become increasingly difficult as thedem<strong>and</strong> for <strong>and</strong> supply of resources changes <strong>and</strong> b) short­term personalgain wins out over long­term social needs or benef<strong>its</strong> (Sreelakshmi, 2005).6.10 Sources of water in the study areaHouseholds, agriculture, <strong>and</strong> industrial sectors are three consumers ofwater in the study area. Since there are only very few industrial un<strong>its</strong>, thefirst two sectors consumed about 80 per cent of the available water.Although there are a few tanks <strong>and</strong> ponds, the major sources of water inthe study area are wells <strong>and</strong> Peechi Reservoir (Manali river).91

6.11 Irrigation vs. Drinking waterBefore examining the conflict between irrigation <strong>and</strong> drinking watersectors, an underst<strong>and</strong>ing of the major features <strong>and</strong> objectives of theReservoir will help to throw more light to this conflict. The Peechi is one ofthe major irrigation projects in the State. The project was started in 1947<strong>and</strong> commissioned in 1959. Water was first let out for irrigation in 1953.One of the major objectives of the Reservoir was to supply water to theagricultural sector. The height of the Dam is 79 m <strong>and</strong> water supply inletis at 53.34 m. Right <strong>and</strong> left bank canals for irrigation are at 56.39 m<strong>and</strong> 67.06 m. respectively. They irrigate an area of 18,623 ha. mostly inThrissur district.Peechi Reservoir provides drinking water to Thrissur Corporation <strong>and</strong> 9Panchayats nearby Thrissur Corporation. The water dem<strong>and</strong> of ThrissurCorporation is fully met by Peechi Reservoir. There is a water purificationplant in Peechi with 50 Million litres (Ml) production capacities per day(total production in a year is 365 x 50 Ml). In 1965, 14.5 Ml. was thecapacity of the plant <strong>and</strong> was used <strong>its</strong> capacity only for ThrissurMunicipality. The authority maintains PH of water as 7, turbidity below 5<strong>and</strong> does chlorination for purification.The turbidity of water is usually normal <strong>and</strong> it creates problem only inpeak days of monsoon. So, the average cost of purification of Peechiwater is very low. (below Rs.2 per 1000 litres ). Water level reaches below200 ft. in summer season. As per the estimates of KWA, per capitaconsumption of water per day was 40 litres in 1982 <strong>and</strong> it increased to140 litres now. If the water from Peechi is not supplied, there is noalternative arrangement for drinking water in Thrissur Corporation.As stated earlier, one of the objectives of the Dam was to supply water tothe agriculture sector, particularly to the Kole l<strong>and</strong>s in Thrissur district.The water release from Peechi showed a shift in favour of drinking watersince 1983 (Indira Devi, 2002). Total inflow of the water during 1983 was155.79 Mm 3 of which 143.73 Mm 3 was released from the reservoir,accounting for 92 per cent. Of the total water released, irrigation92

accounted for 87 per cent <strong>and</strong> rest for drinking purpose (Table 6.7). Butduring 1983­2002, quantity of water released for irrigation reduced from143.73 Mm 3 to 58.64 M m 3 , while quantity released for drinking purposeincreased from 10.95 Mm 3 to 20.07 Mm 3 , indicating that the drinkingwater supply from the Reservoir doubled at the cost of irrigation. It wasfound that about 80 per cent of the people, having water connection in theurban areas were higher income group.Table: 6.7 Water release data of Peechi irrigation project during 1983­2002 (Mm 3 )YearQuantityreleased fordrinkingQuantityreleased forirrigationTotalquantityreleasedTotalinflow1983 10.95 126.358 143.731 155.7941984 10.98 129.37 146.773 153.131985 10.95 135.727 153.1 156.04811986 10.95 70.665 88.038 97.671987 10.95 70.763 88.136 181.6711988 10.98 158.525 175.928 142.7461989 10.95 142.108 159.481 146.6431990 13.146 114.291 133.86 194.84551991 15.33 170.818 192.571 197.2261992 15.372 140.454 162.249 130.4891993 15.33 129.314 151.067 191.6431994 15.33 173.795 195.548 210.1751995 15.33 126.105 147.858 130.4891996 19.113 102.02 127.556 68.2491997 20.075 165.332 191.83 116.50831998 20.075 122.817 149.315 NA1999 20.075 75.9708 96.046 NA2000 20.13 111.863 105.013 NA2001 20.075 55.139 52.585 NA2002 20.075 71.61 58.649 NASource: Kerala Engineering Research Institute, Peechi, Kerala93

6.12 Conflict among farmersSide by side with decline in the irrigation water supply from the reservoir,there existed distributional inequality; that is use of water by the farmers,in the head, middle <strong>and</strong> tail end regions was not in uniform. Forinstance, Indira Devi (2002) estimated that water availability in head, middle<strong>and</strong> tail end regions were 14.16 m 3 /day/ha, 6.93m 3 /day/ha <strong>and</strong> 4.7m 3 /day/ha. Suresh (2000) estimated irrigation water use by head farmersas 38 ha cm <strong>and</strong> 4.2 ha cm by the tail end farmer. Our estimate showedthat use of water by the head region was 12.98 m 3 /day/ha, middle region7.69 m 3 /day/ha <strong>and</strong> tail end region 5.6 m 3 /day/ha. Major reasons for thelow availability of water in the tail enders were due to lack of propermaintenance of canals <strong>and</strong> decrease in the number of days water supplied.The productivity of a crop is the result of combined effect of various inputs.Since no production function study was undertaken here, it was not easyto identify the effect of one input on productivity. However, based on theassumption that other inputs are being applied similarly by the farmers,the productivity differences of crops in head, middle <strong>and</strong> tail end of theirrigation canals in comm<strong>and</strong> areas of Peechi may be due to differences inthe availability of water (Table 6.8). The timely supply of sufficient waterassumes great significance in the critical growth stages of the crops.Table: 6.8 Productivity differences of selected crops in head, middle <strong>and</strong> tailend regions of Peechi Irrigation Project (kg/ha) 2005­06Crops Head Middle Tail endRice 3068 2898 2680Banana 5899 5641 5269Coconut (nuts/ha) 8229 8108 8029The average productivity of the farmers in head, middle <strong>and</strong> tail end areasshows variations; the productivity of the head region is higher than that ofother two regions mainly due to timely <strong>and</strong> sufficient use of water fromthe canals. A change in cropping pattern has also resulted in aggravation94

of water shortage in the study area. For instance, paddy l<strong>and</strong> has anability to hold water for a long time, which helps to maintain water tablein a particular area. This situation is no longer prevalent as paddy is beingincreasingly substituted with banana on a large scale, resulting in dryingup of wells or drastic reduction of water tables in the down stream areas.6.13 Local level conflictsIt is generally said that Kerala has highest density of family based opendug wells <strong>and</strong> on an average; there are more than 120 wells/km 2 . Morethan 70 per cent of the State’s population gets drinking water from thehouse compound’s well. During the summer season, because of decline ofwater table, at least 10 per cent of wells will be dried up, causing acutewater problems to 15­20 lakhs people (Indira Devi, 2002). In the studyarea about 75 per cent of the households have wells in their housecompounds. As our data shows, water table in the wells declined fromNovember to May in upl<strong>and</strong> area (Olakara) <strong>and</strong> October to May in Kavallur.But the decline was more in upl<strong>and</strong> areas where water shortage was more.According to one estimate by the Panachery Panchayat, where the PeechiIrrigation Project is located, out of 10720 households in the Panchayatabout 60 per cent of them were affected by water shortage during 2005­06. There were about 4426 wells in the Panchayat of which only 2639wells (60 per cent of the total), gave water through out the year. Therewere 170 tube wells in the Panchayat of which only 118 wells or 70 percent provided water through out the year. Kerala Water Authority hadgiven water connection to 418 houses, 1049 households got waterpartially from public tap <strong>and</strong> about 388 households depend on publicwells during the reference period. Thus, water shortage was very acute inthe Panchayat whereas water problems in Thrissur Corporation have beensolved (Government of Kerala, 2006). The local people have strong protestagainst the present state of affair. They asserted that Water Authorityshould solve their water problems first <strong>and</strong> then supply to other parts ofthe Thrissur Corporation.95

Chapter 7LINKAGES BETWEEN UPLAND AND DOWN STREAM AREASWatersheds are drainage or catchment areas where water gathers <strong>and</strong>flows downstream to feed rivers <strong>and</strong> lake, before running into oceans.Thus, it is evident that upl<strong>and</strong> <strong>and</strong> downstream areas of a watershed areinterlinked. However, the nature <strong>and</strong> extent of linkage may be different indifferent watersheds. This section is mainly devoted to trace out thelinkage between upl<strong>and</strong> <strong>and</strong> downstream areas <strong>and</strong> also linkage betweenwatershed <strong>and</strong> marketshed which is defined as the geographical area <strong>and</strong>associated population that has real or potential relationship with aparticular centre. Marketsheds are selected in areas where smallholdershave at least minimal access to water <strong>and</strong> markets (ADB, 2003). Anattempt is also made to examine some of the vital environmental problemsin the watershed, which has implications on <strong>its</strong> future development.7.1 Upl<strong>and</strong>Before the construction of Peechi Dam, the upl<strong>and</strong> areas of this watershedwere free from environmental problems. Over the last three decades, theupl<strong>and</strong> areas have come under increasing threats. Pressure frompopulation growth, deforestation, mining, unsound agricultural practices,tourism <strong>and</strong> increasing construction activities are all taking their toll inthe upl<strong>and</strong> areas. Initially, the settlers attempted to cultivate subsistencecrops like rice <strong>and</strong> tapioca in the upl<strong>and</strong> areas. As paddy was cultivatedin terraced areas, the soil erosion was not severe in this area. The tapiocacultivation, however, triggered soil erosion, but it was only in limitedareas initially. Due to a small population in the initial period, the area ofcultivation was limited <strong>and</strong> consequently the impact of tapioca cultivationwas not very high <strong>and</strong> there was not much silting in the Reservoir.Eventually, the population increased at an exponential rate in the areawith resulting competition <strong>and</strong> conflicts over l<strong>and</strong> <strong>and</strong> other resources<strong>and</strong> a new system of cropping viz., mixed cropping­ a combination ofsubsistence <strong>and</strong> horticultural crops ­ was introduced in the area. The marketfor horticultural crops exp<strong>and</strong>ed with an increased dem<strong>and</strong> <strong>and</strong> consequently97

<strong>its</strong> prices also showed a boom assuring the farmers’ food security <strong>and</strong>cash savings. When the price of horticultural crops showed further increase,more l<strong>and</strong> was brought under these crops. This was done mainly byencroaching the nearby forested areas <strong>and</strong> partly by reducing the area underpaddy. During 1970­1985 periods, this area also witnessed a massive inflowof settlers <strong>and</strong> majority of them were farmers from central Kerala. Thisbrought about two major developments in the areas. First, the l<strong>and</strong> priceincreased significantly which forced the farmers to encroach forest areas.Secondly, since the l<strong>and</strong> became unproductive over the years due to constant<strong>and</strong> indiscriminate exploitation, the productivity showed a declining trendwhich in turn forced the farmers to adopt more lucrative crops like rubber<strong>and</strong> banana in place of traditional crops like paddy. This change in croppingpattern assured relatively more profit per unit area <strong>and</strong> an increased cashincome. This input intensive cropping practice, eventually increased soilerosion <strong>and</strong> a decline in biodiversity followed, which led to anunsustainable farming regime. This culminated in reduced employmentamong agricultural workers, particularly among women in the area as thetraditional cropping provided more opportunities for women folks.A major impact due to the input intensive cropping regime was theincreased use of pesticides <strong>and</strong> l<strong>and</strong> management practices, whichaccelerated the rate of sedimentation, leading to diminish the waterquality <strong>and</strong> quantity in the downstream.7.2 <strong>Change</strong>s in downstream areasOur survey revealed that during 1970’s about 90 per cent of the people inthe down stream areas of Manali watershed were farmers <strong>and</strong> agriculturalworkers. Ironically, over the years it was reduced to 29 per cent. Paddycultivation <strong>and</strong> homestead farming were the major areas of agriculturaloperations in the downstream areas. Paddy was cultivated twice,depending on monsoon. Farmers used the water from the upl<strong>and</strong> areas<strong>and</strong> channels in addition to the irrigation water supplied from PeechiReservoir. Over the years, there have been a number of changes in theagricultural sector in the down stream areas. First, because of subdivision<strong>and</strong> fragmentation, the l<strong>and</strong> size of each family was reduced significantly.98

Secondly, due to low prices, the paddy cultivation was not remunerative<strong>and</strong> some people substituted farming to other jobs <strong>and</strong> some peopleleased out the l<strong>and</strong> for banana cultivation as it provided more profit perunit area. Although banana cultivation provided higher income, itgenerally reduced the employment opportunity of the women workers asmentioned elsewhere. But <strong>its</strong> impact on ecology of the region was severe.Due to conversion of wetl<strong>and</strong>s to banana <strong>and</strong> other horticultural crops,the period <strong>and</strong> quantum of water held in the field was considerablyreduced, resulting in lower water table <strong>and</strong> water shortage. Shortage ofwater during summer months is a common phenomenon in the area,while such a situation was not prevalent in 30 years back.The interaction of bio­physical factors such as soils, water, plants <strong>and</strong>animals enables the watershed to perform many vital functions like waterstorage, storm protection <strong>and</strong> flood mitigation (Ecological system).Similarly, the watershed provides many economic benef<strong>its</strong> like watersupply, agriculture, erosion control, among others (Economic system). Achange in the economic system (ill managed <strong>and</strong> over exploitedwatersheds) poses serious problems to ecological system of the upstream<strong>and</strong> downstream areas. The cost of damage can be seen in eroded soil,l<strong>and</strong> slides, low water quality <strong>and</strong> quantity, loss of biodiversity <strong>and</strong>ecological imbalances which affect the production. A change in productionwill generally bring about changes in dem<strong>and</strong>/supply <strong>and</strong> or prices(Market shed). In other words, there was a close linkage between biophysical<strong>and</strong> socio­economic factors of the watershed <strong>and</strong> also betweenthe watershed <strong>and</strong> ‘marketshed’ ( Fig. 7.1). This interaction was one of themajor underlying factors of l<strong>and</strong> use changes in the selected watershed.The l<strong>and</strong> use change in a given watershed is a function of variousparameters as given below.<strong>L<strong>and</strong></strong> use <strong>Change</strong> = f {Socio­economic drivers/Marketshed (Price of maincrops, upstream/downstream, price of other crops, cost of production,price policies, other income generating activities, real estate boom, absenteel<strong>and</strong>lords, adoption of innovative technology/crops, etc.) <strong>and</strong> Ecologicaldrivers (Critical factors of production, physiography/ geographical factors,rainfall <strong>and</strong> other climatic factors, ecosystem resilience etc.).99

Fig. 7.1100

7.3 Environmental problemsSeveral environmental problems are observed in the region, of which themost important is rock mining in the upl<strong>and</strong> areas <strong>and</strong> s<strong>and</strong> <strong>and</strong> claymining in the down stream areas. With the availability of new machines,methods <strong>and</strong> transportation facilities, rock mining in the upl<strong>and</strong> areashas become a productive activity <strong>and</strong> in the selected upl<strong>and</strong> area,organized rock mining is very much prevalent. In the context of expansionof construction activities in the downstream areas, mining provides highprofit to the miners <strong>and</strong> employment to the local people. But in the fragileupl<strong>and</strong> areas <strong>its</strong> environmental effects are large; as it often effects smalll<strong>and</strong> slides, <strong>and</strong> enhances sedimentation, surface dumps <strong>and</strong>trenches/open p<strong>its</strong>. It also causes atmospheric pollution <strong>and</strong> healthproblems among people living in nearby areas.Karuvannur river basin is one of the areas in Thrissur district where clay<strong>and</strong> s<strong>and</strong> mining is concentrated (Sreekumar <strong>and</strong> John Thomas, 2006).Majority of tile factories <strong>and</strong> brick making un<strong>its</strong> in Thrissur district arelocated in <strong>and</strong> around this area. Clay mining is very severe in areas likePudukad, Parpukara, Nenmanikara, Poruthussery, Madayikonam, Thottipal,Anathapuram, Amballur, Rappal, Kallor, <strong>and</strong> Thrikkur. In these places,the entire paddy l<strong>and</strong>s were used for clay mining <strong>and</strong> as a result paddyfields have been converted into water logging p<strong>its</strong>. With the market exp<strong>and</strong>ingfor s<strong>and</strong>, the contractors continued s<strong>and</strong> mining from these waterlogged p<strong>its</strong>exacerbating the damage caused on the ecosystem. A severe ecologicalimplication due to s<strong>and</strong> mining is destruction of a thick s<strong>and</strong> horizonwhich lies below the clay zone that serves as a potential aquifer of thearea. Its removal will lower water storage/holding capacity of wetl<strong>and</strong>ssignificantly (Sreekumar <strong>and</strong> John Thomas, 2004). Excessive s<strong>and</strong> miningis the most serious problem that has contributed mostly to the destructionof rivers of Kerala (Gopinathan Nair, 2006). There is no official data oncollection of s<strong>and</strong> from Manali river or Karuvannur river basin <strong>and</strong> hencethe quantum of damage could not be estimated in the study. But a number ofPanchayats through which the river flows allow people to collect s<strong>and</strong>. In101

addition, smuggling of s<strong>and</strong> by truck owners is a regular activity here. One ofthe unofficial estimates indicated that the s<strong>and</strong> extraction from the river basinexceeded more than 10 lakhs tonnes during 2005­06. This is said to besignificantly higher than what is naturally deposited in the river. The s<strong>and</strong>has a major role in purification of water <strong>and</strong> also conservation of water byreducing the speed of flow of water especially during rainy season (GopinathanNair, 2006). The excessive s<strong>and</strong> mining results in lower water table, intrusionof saline water into the river <strong>and</strong> slumping <strong>and</strong> caving in riverbanks, leading todegradation of watershed <strong>and</strong> finally slow death of the river.102

Chapter 8CONCLUSIONS AND RECOMMENDATIONSConclusionsDrastic changes in l<strong>and</strong>use have occurred, particularly conversion offorest l<strong>and</strong> to agricultural l<strong>and</strong> in the study area during the analysisperiod 1960­61 to 2004­05. Encroachment <strong>and</strong> conversion of forest l<strong>and</strong>to agricultural l<strong>and</strong> has been a continuous activity in the study area, inspite of laws to prevent this. For instance, during 1996­2004, area underagriculture increased by 50 per cent, mostly through conversion offorests. Population increase, encroachment, agricultural expansion <strong>and</strong>construction of dam are the major socio­economic drivers that influencedl<strong>and</strong> use changes in Manali watershed.A shift from subsistence to commercial crops over a period of time wasrecorded both upl<strong>and</strong> <strong>and</strong> down stream areas of watershed. Thishappened in response to price increase of commercial crops. Obviously,this change has brought about an increase in income of the farmers.However, their per capita income remained less than that of the district<strong>and</strong> State averages. Further, the low saving <strong>and</strong> high borrowing furtherworsened their economic condition. Moreover, the changes in croppingpattern reduced food security, employment opportunity <strong>and</strong> wateravailability in the study area.As regards to climate, there was no indication for the decrease in rainfallsince 1966. However, yearly variations did occur, which was notabnormal. The river flow discharge observed since 1963 also revealed thatthere was no tendency for <strong>its</strong> decrease during the entire period. Here also,there were some irregular fluctuations from year to year.In the forested watershed at Olakara, the base­flow persisted tillDecember in contrast with the Kavallur watershed, where it stopped inNovember <strong>its</strong>elf. More sustained streamflow at Olakara as compared toKavallur favours the idea of a forested catchment as compared to103

predominantly agricultural catchment. This indicates the need forundertaking conservation <strong>and</strong> afforestation measures in the degradedforest areas for better availability of water. However, it is interesting tonote that there was no sustained streamflow from a moist deciduousforest, which is leafless during the dry season.Plant diversity analysis carried out in Olakara area shows that habit wise,122 are herbs, 33 shrubs, 54 climbers <strong>and</strong> 50 are trees. Among the 259species enumerated only 29 are Peninsular Indian endemics. Theoccurrence of Securinega virosa, Careya arborea, Catunaregam spinosaetc. indicates that the area was prone to seasonal fire in the past.Sedimentation was low in a forested watershed whereas in the upperreaches of downstream areas, which were highly degraded, it was high.Annual sedimentation in Peechi Reservoir was 0.9 per cent. This can bereduced further if the forest areas are properly afforested or conserved.Total economic value of Peechi wet l<strong>and</strong>s was approximately Rs. 1844lakhs ( per hectare value amounted to Rs. 146039). Willingness to pay forregular <strong>and</strong> steady supply of water from Peechi Reservoir was alsoassessed. About 80 per cent, who used drinking water from Peechi, werewilling to pay more for timely <strong>and</strong> regular supply of water whereas 20 perdid not agree for any increase in price of water.Peechi water supply could solve the drinking water problems in Thrissurtown to a great extent where as there existed water shortage in nearbypanchayats where the Peechi dam is located during summer months. Itwas found that about 80 per cent of the people who have waterconnection in the urban areas belonged to rich or upper middle class.Proper strategy may be evolved to solve the water shortages in theagricultural sector <strong>and</strong> also water requirements of the poor.In short, it was highlighted that whatever happens in upl<strong>and</strong> areas has amassive impact on downstream area <strong>and</strong> vice versa as both the areas areinterlinked. Further, the study also indicated that both watershed <strong>and</strong>‘market shed’ are closely inter­connected <strong>and</strong> as a result of which a104

change in dem<strong>and</strong>/supply/prices of commodities has <strong>its</strong> own impacts­either positive or negative ­ on watershed.RecommendationsForested upl<strong>and</strong> areas have an essential role in sustaining <strong>and</strong> protectingwater resources <strong>and</strong> also maintaining the quality of water yield. Upstreammanagement of forests influences availability <strong>and</strong> uses of water indownstream areas. Thus, emphasis should be given to enrichmentplanting especially in degraded upl<strong>and</strong> areas. While implementingenrichment planting programmes in the upstream areas, due stress mayalso be given to shrubby indigenous species, which play an important rolein checking soil erosion.An effective watershed management plans taking upstream <strong>and</strong>downstream <strong>and</strong> also watershed <strong>and</strong> market shed linkages intoconsideration, should be formulated <strong>and</strong> implemented. Separate microplanning with appropriate cropping pattern <strong>and</strong> effective water <strong>and</strong> l<strong>and</strong>management practices for both upl<strong>and</strong> <strong>and</strong> downstream areas in a microwatershed shall be prepared. In addition, a macro planning at river basinlevel, combining all micro plans at the watershed level may be formulated<strong>and</strong> implemented. A watershed management approach, focusing variousaspects of forestry, agriculture, hydrology, ecology, soils, <strong>and</strong> climatologyto find ways of conserving <strong>and</strong> using l<strong>and</strong> resources, shall be adopted indrawing micro <strong>and</strong> macro level plans. Conservation of paddy field indownstream areas should get a top priority. The implementation of theplan shall be done through effective participation of local people, whichshall prevent further ecological degradation in the study areas.Since the users of water are willing to pay more, proper pricing of waterresources in Peechi Reservoir may be fixed, considering the surplusgeneration <strong>and</strong> equity factors. For instance, a differential pricing based onability to pay may be thought of. A part of the surplus generated throughproper pricing may be used for the afforestation of degraded forest area,which may sustain <strong>and</strong> conserve water resources in Peechi.105

The watersheds that are degraded pose serious problems to environment<strong>and</strong> people. The degradation factors such as rock mining in upl<strong>and</strong> areas,s<strong>and</strong> <strong>and</strong> clay mining in downstream areas, riverbank encroachment, etc.in the study area should be controlled. River bank protection measureslike planting of bamboo or other plants along riverbanks may beencouraged <strong>and</strong> encroachments may be evicted.106

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APPENDIXTHE PLANTS IN THE WATERSHED AREA1. Abrus precatorius L.2. Abutilon persicum (Burm.f.) Merr.3. Acacia caesia (L.) Willd.4. Acacia pennata (L.) Willd.5. Acacia sinuata (Lour.) Merr.6. Acacia torta (Roxb.) Craib7. Acalypha racemosa Wall. ex Baill.8. Achyranthes aspera L.9. Achyranthes bidentata Blume10. Adiantum philippinum L.11. Aerides ringens (Lindl.) C.E.C. Fisch.12. Ageratum conyzoides L.13. Albizia odoratissima (L. f.) Benth.14. Allophylus cobbe (L.) Raeusch.15. Alstonia scholaris (L.) R. Br.16. Andrographis alata (Vahl) Nees17. Anisochilus carnosus (L. f.) Wall. ex Benth.18. Anogeissus latifolia (Roxb. ex DC.) Guill. & Perr.19. Antidesma acidum Retz.20. Aporosa cardiosperma (Gaertn.) Merr.21. Asparagus racemosus Willd.22. Baliospermum montanum (Willd.) Muell.­Arg.23. Bambusa bambos (L.) Voss24. Barleria acuminata Nees – Endemic to Peninsular India25. Barleria prattensis Sant. – Endemic to Western Ghats26. Bauhinia racemosa Lam.27. Bidens biternata (Lour.) Merr. & Sheriff28. Bidens pilosa L. var. minor (Blume) Sherff29. Blumea lanceolaria (Roxb.) Druce30. Blumea virens Wall. ex DC.31. Bolbitis appendiculata (Willd.) K.Iwats.113

32. Bombax ceiba L.33. Bombax insigne Wall.34. Briedelia retusa (L.) A. Juss.35. Briedelia stipularis (L.) Blume ­ Endemic to Peninsular India36. Caesalpinia mimosoides Lam.37. Cajanus scarabaeoides (L.) Thouars38. Calopogonium mucunoides Desv.39. Calycopteris floribunda Lam.40. Canscora diffusa (Vahl) R. Br. ex Roem. & Schult.41. Canthium corom<strong>and</strong>elicum (Burm. f.) Alston42. Carallia brachiata (Lour.) Merr.43. Careya arborea Roxb.44. Caryota urens L.45. Cassia fistula L.46. Catunaregam spinosa (Thunb.) Tirveng.47. Cayratia pedata (Lam.) A. Juss. ex Gagnep. var. glabra Gamble ­Endemic to Southern Western Ghats48. Cayratia trifolia (L.) Domin49. Celastrus paniculatus Willd.50. Centotheca lappacea (L.) Desv.51. Centrosema molle Benth.52. Ceraptopteris thalictroides (L.) Brongn.53. Chassalia curviflora (Wall. ex Kurz) Thw. var. ophioxyloides (Wall.)Deb & Krishna54. Chlorophytum nimmonii (Graham) Dalz.55. Chromolaena odorata (L.) King & Robins.56. Cipadessa baccifera (Roth) Miq.57. Cissampelos pareira L. var. hirsuta (Ham. ex DC.) Forman58. Cissus latifolia Lam.59. Cleistanthus collinus (Roxb.) Benth. ex Hook.f.60. Clematis gouriana Roxb. ex DC.61. Clerodendrum infortunatum L.62. Commelina diffusa Burm. f.63. Commelina maculata Edgew.114

64. Corchorus aestuans L.65. Cordia wallichii G. Don – Endemic to Peninsular India66. Cosmostigma racemosum (Roxb.) Wight67. Costus speciosus (Koenig) J.E. Smith68. Crotalaria heyneana Graham ex Wight & Arn. – Endemic toSouthern Western Ghats69. Curcuma ecalcarata Sivar. & Indu­Endemic to Southern Western Ghats70. Curcuma vamana Sabu & Mangaly­Endemic to Southern Western Ghats71. Cyathula prostrata (L.) Blume72. Cyclea peltata (Lam.) Hook. f. & Thoms.73. Cymbidium aloifolium (L.) Sw.74. Cynanchum callialatum Ham. ex Wight75. Cyperus iria L.76. Cyrtococcum oxyphyllum (Steud.) Stapf77. Dalbergia lanceolaria L. f. ssp. lanceolaria78. Dalbergia latifolia Roxb.79. Dalbergia volubilis Roxb.80. Dendrophthoe falcata (L. f.) Etting.81. Derris canarensis (Dalz.) Baker ­ Endemic to Western Ghats82. Desmodium gangeticum (L.) DC.83. Desmodium laxiflorum DC.84. Desmodium motorium (Houtt.) Merr.85. Desmodium pulchellum (L.) Benth.86. Desmodium triangulare (Retz.) Merr.87. Desmodium triflorum (L.) DC.88. Desmodium velutinum (Willd.) DC.89. Dillenia pentagyna Roxb.90. Dioscorea bulbifera L.91. Dioscorea oppositifolia L.92. Dioscorea pentaphylla L.93. Dioscorea wallichii Hook. f.94. Diospyros montana Roxb.95. Drosera indica L.96. Drosera peltata Smith115

97. Drynaria quercifolia J.E. Smith98. Ehretia canarensis (Clarke) Gamble ­ Endemic to Peninsular India99. Elephantopus scaber L.100. Embelia tsjeriam­cottam (Roem. & Schult.) DC.101. Eranthemum capense L.102. Eriocaulon xeranthemum Mart.103. Eulophia spectabilis (Dennst.) Suresh104. Ficus hispida L. f.105. Ficus microcarpa L. f.,106. Ficus tsjahela Burm. f.107. Firmiana colorata (Roxb.) R. Br.108. Flemingia macrophylla (Willd.) Prain ex Merr.109. Flueggea virosa (Roxb. ex Willd.) Voigt110. Globba marantina L.111. Gloriosa superba L.112. Gmelina arborea Roxb.113. Gomphostemma heyneanum Benth. var. rottleri Prain ­ Endemic toSouthern Western Ghats114. Grewia abutilifolia Vent. ex Juss.115. Grewia serrulata DC.116. Grewia tiliifolia Vahl117. Gymnopetalum tubiflorum (Wight & Arn.) Cogn.118. Habenaria plantaginea Lindl.119. Haldina cordifolia (Roxb.) Ridsd.120. Hedyotis neesiana Arn.121. Helicteres isora L.122. Hemidesmus indicus (L.) R. Br.123. Hibiscus hispidissimus Griff.124. Hibiscus lobatus (Murr.) O. Ktze.125. Hibiscus lunariifolius Willd.126. Holarrhena pubescens (Buch.­Ham.) Wall. ex G. Don127. Holostemma ada­kodien Schult.128. Hoppea fastigiata (Griseb.) Clarke129. Hydnocarpus pent<strong>and</strong>ra (Buch.­Ham.) Oken ­ Endemic to SouthernWestern Ghats116

130. Hymenodictyon orixense (Roxb.) Mabb.131. Hyptis capitata Jacq.132. Hyptis suaveolens (L.) Poit.133. Ichnocarpus frutescens (L.) R. Br.134. Impatiens minor (DC.) Bennet ­ Endemic to Peninsular India135. Indigofera astragalina DC.136. Ipomoea deccana Austin137. Ipomoea hederifolia L.138. Ipomoea pes­tigridis L.139. Ipomoea pileata Roxb.140. Ischaemum indicum (Houtt.) Merr.141. Jasminum multiflorum (Burm. f.) Andr.142. Justicia japonica Thunb.143. Justicia trinervia Vahl144. Lagen<strong>and</strong>ra toxicaria Dalz.145. Lagerstroemia microcarpa Wight­Endemic to Southern Western Ghats146. Lagerstroemia speciosa (L.) Pers.147. Lannea corom<strong>and</strong>elica (Houtt.) Merr.148. Leea indica (Burm. f.) Merr.149. Leea macrophylla Roxb. ex Hornem.150. Lepidagathis incurva Buch.­Ham. ex D.Don151. Lobelia alsinoides Lam.152. Lindernia caespitosa (Blume) Panigrahi153. Ludwigia hyssopifolia (G. Don) Exell154. Luisia evangelinae Blatt. & McCann ­ Endemic to Western Ghats155. Lygodium flexuosum (L.) Sw.156. Macaranga peltata (Roxb.) Muell.­Arg.157. Mallotus philippensis (Lam.) Muell.­Arg.158. Merremia umbellata (L.) Hall. f.159. Merremia vitifolia (Blume) Hall. f.160. Microstachys chamaelea (L.) Muell.­Arg.161. Miliusa tomentosa (Roxb.) Finet & Gagnep.162. Mimosa pudica L.163. Mitracarpus hirtus (L.) DC.117

164. Mitragyna parvifolia (Roxb.) Korth.165. Mitreola petiolata (Gmel.) Torr. & Gray166. Morinda pubescens J. E. Smith167. Mucuna pruriens (L.) DC.168. Murdannia japonica (Thunb.) Faden169. Murdannia semiteres (Dalz.) Sant. ­ Endemic to Peninsular India170. Murdannia spirata (L.) Brueck.171. Mussaenda frondosa L. ­ Endemic to Peninsular India172. Naregamia alata Wight & Arn. ­ Endemic to Peninsular India173. Naringi crenulata (Roxb.) Nicolson174. Nelsonia canescens (Lam.) Spreng.175. Oberonia mucronata (D. Don) Ormerod & Seidenf.176. Oldenl<strong>and</strong>ia ovatifolia (Cav.) DC.177. Olea dioica Roxb. ­ Endemic to India178. Oplismenus compositus (L.) P. Beauv.179. Ormocarpum cochinchinense (Lour.) Merr.180. Oroxylum indicum (L.) Benth. ex Kurz181. Oryza officinalis Wall. ex Watt ssp. malampuzhensis (Krishnasw. &Ch<strong>and</strong>rasek.) Tateoka ­ Endemic to Southern Western Ghats182. Passiflora foetida L.183. Pavetta indica L.184. Pennisetum americanum (L.) Leeke185. Pennisetum pedicellatum Trin.186. Peristrophe montana Nees187. Persea macrantha (Nees) Kosterm.188. Phyllanthus emblica L.189. Phyllanthus kozhikodianus Sivar. & Manilal190. Phyllanthus retculatus Poir.191. Piper longum L.192. Platostoma hispidum (L.) Paton193. Pongamia pinnata (L.) Pierre194. Porpax jerdoniana (Wight) Rolfe­Endemic to Southern Western Ghats195. Pouzolzia zeylanica (L.) Bennett196. Pseudarthria viscida (L.) Wight & Arn.118

197. Pterocarpus marsupium198. Pueraria tuberosa (Roxb. ex Willd.) DC.199. Radermachera xylocarpa (Roxb.) K. Schum.­Endemic to Peninsular India200. Rhinacanthus nasutus (L.) Kurz201. Rhynchosia rufescens (Willd.) DC.202. Rhynchostylis retusa (L.) Blume203. Rottboellia cochinchinensis (Lour.) W. D. Clayton204. Sapindus trifoliatus L.205. Sauropus quadrangularis (Willd.) Muell.­Arg.206. Schleichera oleosa (Lour.) Oken207. Scleria rugosa R. Br.208. Selaginella sp.209. Setaria palmifolia (Koenig) Stapf210. Sida acuta Burm. f.211. Sida alnifolia L.212. Sida beddomei Jacob ­ Endemic to Southern Western Ghats213. Sida cordata (Burm. f.) Borss.214. Sida mysorensis Wight & Arn.215. Spatholobus parviflorus (Roxb. ex DC.) O. Ktze.216. Spodiopogon rhizophorus (Steud.) Pilger217. Spondias pinnata (L. f.) Kurz218. Stachyphrynium spicatum (Roxb.) Schum. ­ Endemic to SouthernWestern Ghats219. Staurogyne glauca (Nees) O. Ktze.220. Staurogyne glutinosa (Wall. ex Clarke) O. Ktze.221. Sterculia guttata Roxb. ex DC.222. Sterculia urens Roxb.223. Sterculia villosa Roxb. ex Smith224. Stereospermum colais (Buch.­Ham. ex Dillw.) Mabb.225. Streblus asper Lour.226. Strychnos nux­vomica L.227. Synedrella nodiflora (L.) Gaertn.228. Tabernaemontana alternifolia L.­Endemic to Southern Western Ghats229. Tamilnadia uliginosa (Retz.) Tirveng. & Sastre119

230. Tectaria coadunata (Js.Sm.) C.Chr.231. Tectona gr<strong>and</strong>is L. f.232. Tephrosia canarensis Drumm.233. Teramnus labialis (L.f.) Spreng.234. Teramnus mollis Benth.235. Terminalia bellirica (Gaertn.) Roxb.236. Terminalia crenulata Roth237. Terminalia paniculata Roth – Endemic to Peninsular India238. Tetrameles nudiflora R. Br.239. Thespesia lampas (Cav.) Dalz. & Gibs.240. Tinospora cordifolia (Willd.) Miers.241. Tragia involucrata L.242. Triumfetta rhomboidea Jacq.243. Tylophora tetrapetala (Dennst.) Suresh var. tenuissima (Roxb. exWilld.) Swarup.244. Typhonium bulbiferum Dalz. ­ Endemic to Western Ghats245. Uraria rufescens (DC.) Schind.246. Urena lobata L. ssp. lobata247. Urena lobata L. ssp. sinuata (L.) Borss.248. Utricularia graminifolia Vahl249. V<strong>and</strong>a testacea (Lindl.) Rchb.f.250. Vernonia divergens (Roxb.) Edgew.251. Vigna pilosa (Roxb.) Baker ­ Endemic to Peninsular India252. Vigna umbellata (Thunb.) Ohwi & Ohashi253. Wrightia tinctoria (Roxb.) R. Br.254. Xenostegia tridentata (L.) Austin & Staples ssp. hastata (Desr.)Panigrahi & Murti255. Xylia xylocarpa (Roxb.) Taub.256. Zanthoxylum rhetsa (Roxb.) DC.257. Zingiber neesanum (Graham) Ramam. ­ Endemic to Western Ghats258. Zingiber wightianum Thw.259. Ziziphus oenoplia (L.) Mill.260. Ziziphus rugosa Lam.120